[mikeash]

There are many cases where guilt can be proven sufficiently, both to assess insurance responsibility and legal culpability.

Just because New Jersey has decided to punt on the whole question doesn't mean it's impossible to answer in all cases. Sure, there will be cases where somebody kills somebody else due to negligence and they get away with it because it can't be proven. People sometimes go free after murdering people with guns and knives because the crime can't be proven too, but that's not a reason to give up on prosecuting all murders.