Insurance group Churchill has brought a case against a teenage girl they say was partly responsible for being knocked down by a car.
The insurer contends its customer, who struck Bethany Probert, then 13, while pulling into the side of a country lane to avoid oncoming vehicles, cannot be held entirely to blame as the teenager should have known about the need to be visible at night.
The case is the first to question a child's culpability in an accident, and the first in 20 years involving a victim's responsibility for walking on the road at night, according to Bethany's solicitors.
Bethany, who is now 16, was returning home by foot from a riding school on a narrow, unlit lane with no footpath, when Paul Moore's Saab 9-3 struck her, leaving her with brain damage causing memory loss, as well as physical disabilities.
Churchill's lawyers argue that she should have known from her training with horses about the need to be visible at night, saying the precautions Bethany failed to take "should have been obvious to a girl of her age."
While the case has already reached the High Court, where the judge ruled against Churchill, saying Bethany's decision to walk home was "ill-informed but not culpable" and Mr Moore's 50mph speed was too fast for such a road in darkness, the Court of Appeal has allowed Churchill to take the issue further. If the judges rule against Bethany at appeal, they can cut any payout proportionately by the amount they feel she was to blame.