In reply to wercat:
> whether the pedestrian voluntarily accepted responsibility is debatable - whether or not the pedestrian took on any liability is an even further step which would be even harder to establish.
They are very much related. Liability is a position in relation to a loss that is established through responsibility (amongst other factors).
> Drivers have an obligation to evaluate a task, not just obey the hand signals of a stranger (unless it's someone acting in an official capacity.
You can point to this as a legal position? Reference? In some vehicles, with poor visibility, the use of an ad hoc banksman might be the only way to safely complete a particular manoeuvre in a particular set of circumstances. The fact that a driver has the primary responsibility, does not mean that negligence on the the part of the other party would be ignored if it came to court.
As I said, I very much doubt that this applied here (and would be even harder to prove), but I do think that asserting that the driver must be 100% at fault, purely because they were the driver, is too simplistic.