Contributory Negligence Update: Owens v Lewis [2024] EWHC 609 (KB)

1.         HHJ Keyser KC, sitting as a Judge of the High Court, has been contributory this week to the canon of judgments which inform practitioners and Courts alike as to how to go about the assessment of contributory negligence. 

The background

2.         The Claimant, Owens, was one of three passengers on a quad bike being driven along a public highway by the Defendant.  The quad bike was not intended to carry passengers[1].  The Claimant came off the bike as it travelled along the highway at a dangerous speed, and suffered serious injury, including a traumatic brain injury. 


3.         The Claimant was 15 years old at the time of the accident, whilst the Defendant was 16 ½ years old.


4.         The Defendant admitted primary liability for permitting the Claimant to travel on the quadbike, but nevertheless sought a deduction of 65% for contributory negligence because the Claimant: 


  1. Agreed to be carried on a quad bike that was not designed to carry passengers;
  2. Positioned himself on the quad bike in such a way as to be vulnerable to coming off it; and
  3. Did not wear a motorcycle helmet. 


5.         It was accepted on behalf of the Claimant that he was at fault for agreeing to be carried as a passenger and that this fault was increased by the fact that he was not wearing a helmet. He nevertheless sought to mitigate the deduction to no more than 20%.


6.         There was evidence from neurologists that if the claimant had been wearing a properly secured motorcycle helmet, the scalp laceration, the skull fractures and the underlying acute subdural haematoma would have been avoided.  The brain injury would have been mitigated; but the experts disagreed as to the extent of that mitigation.


The Law

 7.         As was had regard to in Owens:


8.         Pursuant to s.1 (1) Law Reform (Contributory Negligence) Act 1945 (“the Act”): 


Where any person suffers damage as the result partly of his own fault and partly of the fault of any other person or persons, a claim in respect of that damage shall not be defeated by reason of the fault of the person suffering the damage, but the damages recoverable in respect thereof shall be reduced to such extent as the court thinks just and equitable having regard to the claimant’s share in the responsibility for the damage.” [emphasis added]


9.         In Jackson v Murray [2015] UKSC 5 it was determined that the application of s.1 (1) of the Act necessitates taking into account both the blameworthiness of the parties and the causative potency of their acts (since those concepts are different), with the apportionment of responsibility being: 


inevitably a somewhat rough and ready exercise (a feature reflected in the judicial preference for round figures), and that a variety of possible answers can legitimately be given… Since different judges may legitimately take different views of what would be just and equitable in particular circumstances, it follows that those differing views should be respected, within the limits of reasonable disagreement.


Holistic Consideration 


10.       In Owens, the Judge reminded himself that it is a defendant who bears the burden of proving that a claimant was contributorily negligent, and the assessment of the discount for any contributory negligence involves weighing the parties’ relative blameworthiness and the causative potency of their actions.  In any case it is necessary to consider the components of s.1 (1) of the Act not as being “separated by watertight compartments”, rather, the decision as to a reduction and what was just and equitable must rest on “a holistic consideration” having regard to all matters.


11.       Since relative blameworthiness was part of the test to be applied, the Judge stated that as a starting point the Defendant’s admission of liability required “unpacking”. The Defendant’s carrying of a passenger on a vehicle which was unfit to do so was not the end of the matter. The vehicle was being driven on a public road at an excessive speed. None of his passengers were wearing helmets. None of his passengers were properly secured to the quad bike, with those at the back perched over the side with only the rack to singlehandedly grip.  The passengers were all holding dogs.


12.       As to the Claimant’s conduct, the Judge stated that it was “more rational” to consider the three allegations against the Claimant as aspects of a “single bad decision” – the decision to accept a ride on a quad bike. The first decision inevitably led to the other two outcomes –  sitting in an unsafe position and not wearing a helmet (none being available).  The Claimant had not made three separate bad decisions, but one.


13.       As to the causative potency of the negligent acts by both parties, the Judge noted that this concept is not the same as “but for” causation. An accident in which a pedestrian is knocked down by a speeding car could have been avoided “but for” the presence of both, but the causative potency of the excessive speed is greater because the pedestrian is not independently negligent.


14.       In the course of argument, the Judge raised an issue of the Defendant’s age and whether that was a relevant factor in assessing his culpability. On the facts of the case the matter was not considered central, since the Defendant’s actions would have been negligent to an ordinarily prudent and reasonable 16-year-old boy.  In assessing the Claimant’s negligence, similarly the objective standard of care was to be measured by what is reasonably to be expected of a child of the same age, intelligence and experience.


15.       The Defendant had submitted that since there were multiple allegations of contributory negligence to be considered there should be an aggregation of discounts (for riding on the bike at all, and not wearing a helmet). However, given that the Judge had found that there was one “bad” decision and not more, it was inappropriate to adopt an approach of simply adding up the discounts.  As the Judge said:


“To ride on the quad bike unsecured and without a helmet was, so to speak, presented as a job lot”.


16.       As to the causative potency of the actions of each party, the preponderance of blame lay with the Defendant because he had provided the quad bike (“the source of the danger”), and then had made it more dangerous by driving it at speed.  The fact that the Claimant would not have been injured “but for” his decision to ride on the bike did not make him equally causatively potent.


17.       A 30% reduction for contributory negligence was made. 


Points of Note for Practitioners 

  • It is appropriate to apply a holistic consideration to the assessment of contributory negligence. 


  • The determination of contributory negligence remains entirely fact dependant. 


  • The concepts of blameworthiness and causative potency are central to the assessment of fault, and the actions of both parties must be considered.


  • Where allegations of contributory negligence are multiple, and where the facts of the case are such that the events which lead to the claimant’s fate can be categorised as one “complaint”/a single “wrong decision”, a “merging” approach can be properly implemented as part of the deduction exercise. 


Oliver Carr

Deans Court Chambers

21 March 2024


Judgment (handed down on 19 March 2024) can be found at:


[1] The passengers were all carrying dogs on their laps.