What is the test for determining whether a person is liable for a spondylosis injury?

In my respectful view, the submissions made on behalf of the respondent to support the trial judge's conclusion on the issue of causation are not of assistance because the submissions fail to recognize that the respondent is liable for any injuries caused or contributed to by her negligence and that the presence of other non-tortious contributing causes does not reduce the extent of the liability. In Athey v. Leonati, supra, Major J. made plain that our law does not permit apportionment between tortious causes and non-tortious causes. In this case, what the appellant had to establish was that the accident caused or contributed to the activation or aggravation of the pre-existing spondylosis. The appellant did not have to show that it was the only cause but that it was a cause. Once the burden of proof is met, causation must be accepted as a certainty.