Profile
Derek O’Sullivan KC is recognised as one of the country’s leading Personal Injury practitioners. His practice concentrates on very high value catastrophic injury claims.
Derek was named ‘Personal Injury & Clinical Negligence Junior of the Year’ at the Chambers Bar Awards 2012 and then in 2013, 2014, 2015 and 2016 he was a “Star Individual” in the Chambers Personal Injury ranking for Juniors. He took Silk in 2016 and his practice has grown whilst in Silk. He is a Band 1 Leading Personal Injury Silk in both Chambers and Partners 2025and a Leading Silk in Legal 500 2025.
Derek’s practice concentrates on cases where claimants have been catastrophically injured. He has a particular expertise in relation to brain injury cases- not only cases of severe traumatic brain injury but also “subtle” brain injury cases and cases involving cumulative causes-and spinal injury cases. He is also regularly instructed in catastrophic spinal injury and amputation cases. Derek is familiar with all elements of catastrophic injury cases and is used to leading a team (including extensive medical expert evidence) defending very high value claims.
Derek’s practice now also includes acting as a Mediator. Derek is a CEDR Accredited Mediator and he accepts instructions to act as a Mediator not only in personal injury disputes but across a broad spectrum of civil claims.
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Jameela Sheikh
Assistant Practice Manager
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Jameela Sheikh
Assistant Practice Manager
Areas Of Expertise
“A master tactician and strategic thinker who is always on his game. The depth and breadth of his knowledge across a wide range of issues is second to none”. Chambers and Partners
Liability and Quantum Disputes
Derek’s practice concentrates on cases where claimants have been catastrophically injured. He has a particular expertise in relation to brain injury cases (ranging from cases of the highest severity to subtle TBI cases) and in cases of catastrophic spinal injury. He is also regularly instructed in more serious amputation cases. Derek is familiar with all elements of catastrophic injury cases and is used to leading a team (including extensive medical expert evidence) defending very high value claims.
Quantum
Derek is involved with all quantum issues generally encountered by senior personal injury practitioners dealing with catastrophic injury cases. Issues which he is currently dealing with include: severe brain injury; tetraplegia and paraplegia; claimants in states of minimal consciousness; so-called subtle brain injury cases; major psychiatric decompensation consequential on severe brain injury; amputation; capacity (litigation, management of affairs and deprivation of liberty) and all issues relating to statutory funding and settlements. Derek has been involved with claims with pleaded values in excess of £50M.
Derek has drafted a considerable number of Periodical Payment Orders and has been involved in a number of cases involving PPOs for care as well as PPOs for other heads of loss. He has also been involved in (and drafted PPOs) cases where claimants have provided reverse indemnities.
Road Traffic Accidents
Derek has conducted many cases arising from road traffic accidents and has particular expertise in the interpretation, understanding and challenging of accident reconstruction evidence. Recent cases taken to trial include: Farah v Abdullahi & 5 Ors [2020] EWHC 825, QBD; a case that involved multiple tortfeasors and insurers as well issues including the cause(s) of the claimant’s extensive brain injury, novus actus interveniens and divisibility of injury, as well as Barrow v Merrett [2021] EWHC 792 (QB) and [2022] EWCA Civ 1241 as well as Arkelaos v Phillips [2021] EWHC 2321 (QB): both cases where the defendant driver was absolved of any liability following a collision with a child running into the road ahead of them.
Occupiers’ Liability
Derek has acted in a very considerable number of occupier’s liability claims with the cases dealt with including:
- Liability of the occupiers of woodlands, nature reserves, holiday parks and historic monuments.
- Liability of domestic householders in relation to the 1957 Act.
- Liability of the occupiers of commercial premises (both to visitors and persons attending in the course of their employment) in relation to the 1957 Act.
- Liability of occupiers (both domestic and commercial) in relation to claims by trespassers under the 1984 Act.
Employers’ Liability
Derek has extensive experience of acting for defendants in EL claims; in particular he has extensive experience of acting in multi-defendant cases involving accidents on construction sites. A recent case taken to trial was Harris v Bartrum [2020] EWHC 900 (QB): the employer was found not liable to the employee who suffered catastrophic injury when the articulated lorry and trailer which he had been employed to drive rolled over him.
Public Liability
Derek has extensive experience of acting for defendants in PL claims; ranging from acting for the insurers of occupiers in Occupiers Liability claims to contractors in multi-defendant construction site accidents. A recent example of a PL claim conducted to trial was Jagger v Holland [2020] EWHC 46 (QB).
Rail Claims
For many years Derek has acted for rail companies in relation to claims by passengers, trespassers and claims by injured employees. He is also instructed by Network Rail. He is familiar with the issues in rail claims (including CAHA) and has a good knowledge of the relevant Master Rule books and Railway Standards.
His most recent trial acting in relation to a railway accident involved Derek acting for a train operating company being sued by a passenger after an accident in which the passenger suffered a bilateral amputation after falling between a platform and a moving train: Robinson v Greater Anglian Railways [2018] EWHC 272 (QB). This was an important decision as the claimant sought (unsuccessfully) to argue that the overall safety of train despatch systems on the rail network was unacceptable. Following this Derek acted for Network Rail/GWR in relation to a claim by a passenger who fell down an escalator at the newly modified Reading Station (thereby suffering a catastrophic spinal injury): Snell v Network Rail (2018, QBD; claim discontinued prior to trial).
Derek has acted for a number of rail industry parties having been involved in claims arising from derailment as well as claims by trespassers against Network Rail/TOCs with recent cases including acting for Readypower Group Ltd in Rodger v (1) SPL Powlerlines UK Ltd (2) Readypower Group Ltd (2021, KBD); acting for FHHL in relation to the Various claims arising from the freight train collision and derailment near Logan on 1st August 2015 and acting for First MTR Southwestern Railway following the Collision and derailment at Salisbury Tunnel Junction on 31st October 2021.
Harassment
Derek was part of the Counsel team acting for the former King of Spain in Zu Sayn-Wittgenstein-Sayn v His Majesty Juan Carlos Alfonso Victor Maria de Borbon y Borbon [2023] EWHC 2478. This claim involved the Claimant seeking damages in excess of $120M from the former King of Spain by reason of alleged harassment under the Protection from Harassment Act 1997 and direct infliction of personal injury. This complex claim was subject to a lengthy hearing in June 2023 and Mrs Justice Collins-Rice struck out the entire claim in her judgment handed down on 6th October 2023.
Road Traffic Indemnity/Policy Coverage Claims/Claims involving the MIB
Derek also specialises in acting for Insurers in relation to indemnity disputes and coverage claims arising in road traffic accident claims. Such disputes often give rise to issues relating to s.151 of the Road Traffic Act 1988, Article 75 of the MIB’s Articles of Association and the MIB’s Uninsured Drivers Agreement and the Untraced Drivers Agreement.
Issues in recent cases include:
- Use of the vehicle being outside the scope of SDP Cover enabling insurers to argue no responsibility as contractual insurer or to satisfy a judgment under s, 151 RTA 1988 (and thus have the status of Article 75 Insurer).
- Use of the vehicle being for criminal purposes and thus not being for SDP purposes.
- Passenger claim falling with the s. 151(4) RTA 1988 exemption as well as Clause 8 of the Uninsured Drivers Agreement.
- Article 10 of the Codified Directive and the MIB’s liability (per Colley v Shuker) to satisfy a judgment obtained by a passenger (despite clause 8 of the Uninsured Drivers Agreement).
Policy Coverage and Insurance Claims
Derek has considerable experience in disputes arising by reason of fraud/material non-disclosure/misrepresentation in insurance claims. He has represented insurers in a number of such cases which have proceeded to trial (e.g. Savash v Co-Op General Insurance [2014] EWHC 375 (TCC) and which have dealt with the following
- Presentation of fraudulent documents/use of fraudulent devices in support of claims.
- Presentation of fraudulent claims
- Material non-disclosure in claims
- Material non-disclosure/misrepresentation in insurance proposals.
He is currently involved (for insurers) in a number of such ongoing cases.
Derek has also been instructed in disputes involving policy coverage issues. Cases in this area include insurers refusing to provide public liability cover to a footballer who recklessly injured a fellow player, insurers refusing to provide public liability cover to an insured who injured a friend whilst engaging in horseplay with an air-rifle and insurers refusing to provide cover in respect of a fire which had been wilfully/recklessly started.
As a keen sportsman Derek has always had an interest in sports law cases and has had frequent instructions over the years, having acted in a number of cases, including: negligent tackle claims (football and rugby) assault claims (football, rugby and ice hockey) catastrophic injury arising from golfer’s negligence (jogger blinded by errant golf ball) and a claim against the Football Association (in relation to its rules on banning players following red cards and accumulations of yellow cards). In a recent rugby case Derek was instructed by Cardiff Blues in respect of the High Court claim brought by Owen Williams against the Cardiff Blues and 5 other Defendants following the catastrophic spinal injury suffered by Owen Williams whilst playing in competition in Singapore in 2014.
Derek has also represented a number of sports clubs in respect of employer’s liability claims; including a Premiership rugby club accused of negligence in the rehabilitation of a player after injury.
Derek is also involved in representing amateur clubs and is familiar with claims being brought by members against unincorporated associations.
Derek is currently involved (on behalf of the WRU) in the prospective claims being advanced by former professional rugby union players against the IRB, RFU and the WRU in relation to brain injury and neuro-cognitive disorder.
Derek was appointed to be part of an Appeal Panel of a well known Sports Club dealing with a serious disciplinary matter involving a member. He sat on that panel and was party to the decision reached on the Appeal.
Aviation accidents
Derek is instructed in relation to personal injury claims arising from aviation (both fixed wing and helicopters). Derek has dealt with Montreal convention cases together with non-Convention cases where liability for the accident is in dispute; Derek was instructed by aviation insurers for the aircraft owner in the case of Day v Tasker et al (2009) QBD, Leeds DR- a case regarded as significant in relation to the burden of proof following a helicopter crash.
Derek has also acted for aviation companies and airports in relation to “airside” issues; e.g. he previously acted for a London airport in relation to an industrial illness claim (by an airside worker) involving alleged breaches of the Control of Substances Hazardous to Health Regulations.
Derek has been instructed as Counsel in claims relating to parachute accidents and has acted as a Mediator in relation to two claims for compensation arising from gliding accidents.
Accidents at Sea/on board ships
Employer’s Liability Claims involving accidents at sea or on-board ships; Derek has wide experience in this niche area and has experience of cases involving the following:-
- The Shipbuilding and Ship-Repairing Regulations 1960
- The Docks Regulations 1988
- The Merchant Shipping and Fishing Vessels (Health Safety & Welfare) Regulations 1997
- Liability generally where UK regulations do not apply
Accidents abroad/Cross Border Claims
For many years Derek has acted for insurers in relation to claims arising from personal injury accidents abroad and so conflicts of laws/Rome II issues are frequent in Derek’s practice. He was previously Junior Counsel in a cross border case (involving catastrophic injury) where the damages claim was pleaded at over £40m and then subsequently as Leading Counsel for one of the parties in a cross border claim (resulting from an accident in France) where the damages were pleaded at an even higher figure. Derek has experience of foreign law claims involving: French, Spanish, German, Italian, Norwegian, Belgian, Serbian, Kuwaiti, Brazilian and Maltese law.
Derek has been regularly instructed over the years by insurers in product liability claims; the cases he has been involved in range from being instructed in the “the toxic leather Sofa” Group Litigation (acting for one of the many defendants) to acting for the manufacturers or suppliers of: bicycles, plumbing equipment, air hoses, butane gas canisters, baby changing stations, televisions, truck tyres, car tyres, motorcycle tyres, bicycle tyres etc.
Derek was instructed in the “the toxic leather Sofa” Group Litigation (acting for one of the many defendants) and was recently instructed as Leading Counsel in relation to the claims (including personal injury and property damage) arising from the New Ferry explosion in 2017 as well as being instructed in the prospective claims advanced by former professional rugby players.
Derek’s practice over the years has been one in which ADR has played an important part, both via Joint Settlement Meetings and Mediations, and his experience as a participant in ADR has given him an extensive understanding of the benefits of the ADR process and also the keys to successful ADR.
Derek’s seniority and reputation in the personal injury “marketplace” led to numerous requests for him to act as a Mediator in personal injury litigation (and litigation or disputes, such as coverage and insurance disputes arising between motor insurers following a multi-vehicle accident, arising out of personal injury claims) and Derek now acts as a Mediator, being a CEDR Accredited Mediator.
Derek also believes that there is a clear role for Evaluative Mediation to assist the parties achieve a negotiated compromise and has a “hands on” approach to Evaluative Mediation (when the parties chose that route as part of the Mediation process).
Derek’s skills are ideally suited to the role of Mediator and he has very extensive experience across a wide range of civil disputes; not just in the broad spectrum of personal injury disputes. He is wholly independent, fair-minded and approachable and is committed to helping parties to resolve their disputes through the Mediation process. He is currently instructed to act as a Mediator in a number of cases in which the parties have been unable to achieve settlement by the conventional means of a Joint Settlement Meeting conducted by the parties (or have not believed that a JSM would be a worthwhile exercise due to the differences between the parties).
Derek has also acted as Arbitrator in personal injury disputes or disputes between insurers relating to personal injury claims and is happy to accept such instructions.
