In a situation like that, where there is a presumption of fault on both sides, fault would probably end up being split 50-50. Which in practice usually means each party ends up paying their own costs. A large disparity in costs (as would probably be the case in the example you give) might change that, but it would probably end up having to be decided in court.

(Note that what I am describing would be the case under current law wherever jaywalking is illegal, not just under the hypothetical law I described.)

AZ law

You are

Sec. 19-151. Crossing a roadway. (a) No pedestrian shall cross the roadway within the central business district other than within a marked or unmarked crosswalk. (b) Every pedestrian crossing a roadway outside of the central business district at any point other than within a marked or unmarked crosswalk shall yield the right-of-way to all vehicles upon the roadway. (c) No pedestrian shall cross a roadway where signs or traffic control signals prohibit such crossing.

Who's behavior is more abnormal for the place and conditions when the accident happened?