This is a stupid thread. We've given our opinions as originally requested and are now expected to argue the toss ad nauseum.
At least we've learned that if we come across the scene of an accident, it's best not to stop to assist or warn approaching road users about it in case they crash into your car and then attempt to weasel out of taking responsibility for their excessive speed and inability to control their vehicle.
If Mr Wavy-Arms did in fact have a warning triangle in the boot of his car then I know exactly where he should have put it, and it's not 150m up the road from the scene of the accident...