The way it is here, if you get rear ended, then it is automatically not your fault, because can you honestly say how much damage is caused by the initial impact, and how much by the lady who rear-ended you and pushed you even more into the car in front of you?
I mean, you could barely tap the front car (new bumper, let's say) then you get slammed into final destination 2 style which could destroy half your engine bay!