Which character arc is better?

Which do you guys like more?

i like the one that


Both of these are good to use but the final say comes down to the character.

I feel like you could milk more drama out of the first scenario, where it is undeniably his fault. The second option is also good, but I imagine the survivor's guilt (which he'll have either way) will be a bit less impactful. If it isn't really his fault, there's the possibility he can, instead of learning to forgive himself, focus more on blaming the other person.

Definitely the former. The latter, as Sharkerbob said, is too easy to turn into Revenge Syndrome where she just blames all her problems on the person who hit her car.