Personal injury claims are based on the law of negligence. In order to be eligible for compensation, a defendant or defendant must cause the injury through negligence.

This article reviews the law on causation and looks at what can happen when multiple people are responsible for the injury sustained.

What is causation?

If you have been injured in a slip and fall, motor vehicle accident or as a result of medical advice or treatment, and someone else’s negligent actions were to blame, you may have a claim for compensation. 

To find out whether you have a personal injury claim, consult an experienced lawyer as soon as possible. They will be able to advise you on whether you may meet the requirements for an actionable personal injury claim, which are:

  1. the defendant owed you a duty of care;
  2. the defendant failed to live up to the standard of care expected of them; and 
  3. you sustained an injury that was caused by the defendant’s failure to meet this standard of care. 

It is to this final element that we now turn.

What is the test for establishing causation?

The law permits injured plaintiffs to claim compensation from someone for an injury only if their breach of the required standard of care caused the plaintiff’s injury. There needs to be a connection between the negligent act and the injury. 

Courts use the “but for” test to determine whether this connection exists. This involves examining whether the plaintiff would have suffered some injury but for the defendant’s breach of the standard of care. In other words, if the injury had happened anyway, even without the defendant’s negligent involvement, the defendant’s conduct did not cause the injury.

This can sometimes be difficult for injured plaintiffs to prove on a balance of probabilities, such as in cases of medical malpractice. For example, does the evidence demonstrate that a delay in diagnosing the plaintiff’s illness caused the loss? Or was the person already in such poor health that diagnosing their condition earlier would have made no difference to their treatment options and outcome?

What about where it is impossible to prove “but for” causation?

The Supreme Court of Canada has recognized that it may not always be possible for plaintiffs to use the “but for” test to prove causation. As a result, courts are sometimes prepared to show some flexibility. 

For example, in rare cases, the court may accept evidence that the defendant’s negligent act or omission materially contributed to the occurrence of the plaintiff’s injury. As the Supreme Court said in the case of Clements v Clements:

“This may occur where it is “impossible” for the plaintiff to prove causation on the “but for” test, and where it is clear that the defendant breached his duty of care in a way that exposed the plaintiff to an unreasonable risk of injury. The basis for the exception in these circumstances is that requiring “but for” causation “would offend basic notions of fairness and justice.”

Can multiple people be held liable for causing my injuries?

In times gone by, if multiple negligent parties caused the injury suffered by the plaintiff, each was responsible for the entire loss. The plaintiff could sue one of them, and if they were found to have negligently caused the injury, they were held liable, which was the end of it.

However, times have now changed, with many jurisdictions introducing legislation to provide for contribution among negligent parties. Alberta is no exception, as discussed in the section below.

Importantly, there may be multiple factors that have contributed to a person’s injury. Defendants that have acted negligently and caused the injury cannot escape liability simply by showing that another factor or person has also helped to produce the injury. It is possible for all of the responsible parties to be held jointly liable.

How might a claim work where there are multiple negligent parties?

There are a number of possible outcomes depending on the case’s particular circumstances. 

For example, assuming the loss is indivisible, the injured plaintiff could commence an action against all the negligent parties, and the court may hold multiple people jointly liable. 

Under Alberta’s Tort-feasors Act, a plaintiff cannot bring multiple claims. Section 3(1) provides that receiving a judgment against a single negligent party does not bar an action against any other person who would, if sued, have been jointly liable in respect of the same injury. However:

“the sums recoverable under the judgments given in those actions by way of damages shall not in the aggregate exceed the amount of the damages awarded by the judgment first given”.

As such, a plaintiff is not allowed to recover more than the total compensation assessed. 

Another important concept is contribution, which is also provided for in the Tort-feasors Act. If a plaintiff sues only one of the negligent parties, that party may recover contribution from any other person who would, if sued, have been liable in respect of the same damage. According to section 3(2), the amount of contribution that the party sued by the plaintiff is entitled to recover from the other negligent person is an amount that the court thinks is “just and equitable having regard to the extent of that person’s responsibility for the damage.”

Contact the Personal Injury Lawyers at Cuming & Gillespie LLP for Advice on Personal Injury Claims

If you or a loved one have been injured by someone else, the personal injury lawyers at Cuming & Gillespie LLP in Calgary stand ready to advise you on your prospects of being able to claim compensation to help you with your recovery. Phone us at 403-571-0555 or contact us online to book an appointment for a free consultation.