I understand about picking up the car parts.Not irresponsible, but It is dangerous to other motorists to leave a deer in the middle of the road, not to mention all the car parts someone else had to remove off the road.
As I said, around here, the police may not show up (at least not for a long time. (My husband has hit more deer than he can count, and the police rarely come out unless he specifically requests it for some reason. He doesn't even report all his deer hits to the insurance company unless they cause serious damage. Car insurance can be really expensive here. Moved 15 miles and insurance went up again....)They should have at least reported it.
Edited to add: He can and will move a deer out of the roadway if necessary. If I hit a deer, I know that I would be unable to move it....