Boyd Critoph

The plaintiff, a seven-year-old student, suffered a catastrophic brain bleed after being punched in the head by another student during recess.

The plaintiff sued the school board and its staff for negligent supervision.

The court found that while the punch caused the brain bleed due to the plaintiff's pre-existing undiagnosed arteriovenous malformation, the school board and staff were not negligent.

The general supervision of the schoolyard met the standard of a careful and prudent parent, and the offending student's prior minor misbehaviour did not warrant closer supervision.

The action was dismissed.

During a trial regarding a schoolyard assault that allegedly caused the rupture of an arteriovenous malformation (AVM) in the plaintiff's brain, the plaintiffs moved to exclude an addendum to the defendants' neurosurgical expert report.

The plaintiffs argued the addendum, which contained statistics on the annual risk of an AVM bleeding, constituted a new 'crumbling skull' defence related to damages that was not properly pleaded or disclosed.

The court dismissed the motion, finding that the risk statistic was already patent in the expert's original report and had been accepted by the plaintiffs' own expert.

The court held that a medical fact relevant to causation for liability is equally relevant to the assessment of damages, and its use did not open a new medical field.