This is a good, but tough question. It would depend on the season. I have taken deer before that were shot and some had a lot of waste, or gang green, so it sucks to waste your tag on someone elses bad shooting. The type of deer your describing most likely will die from infection over time or be caught by opportunistic coyotes, if present. I'd probly let it go and hope whoever shot it would track it down, unless its near the end of a bad season ,I would take it. I don't see that as unethical.