If we are to pursue this line we have to accept that in every circumstance all possibilities are reasonably foreseeable and steps can be taken to avoid those possibilities or at least to minimise their impact.
Aye, but this only applies on a personal level of responsibility - you are unreasonably extending it to apply in law.
A few years back i was left hooked by a boy racer at a junction on Lanark Road, and I came off the bike as he had poorly misjudged my rate of progress.
The driver was fully at fault, but privately in my own mind i had to accept personal responsibility for allowing the situation to arise, by neglecting to take primary when approaching the junction.
Its a common enough scenario but there can be no grounds for contributory negligence in law.