Really the gripe should not be a land owner that doesn't allow strangers access but with the guy placing the shot, I never figured it was someone else's issue if I failed to kill and animal on the property I had permission on, 100% operator error IMO!! More productive to channel your frustration into picking your shot and shot placement better next time!!
The warden has no right to enter private property to check on anything unless he has permission, or evidence of a crime/violation and then he needs a search warrant. If the landowner wants to be a jerk and let an animal rot, he can do that. Or he can put a tag on it and keep it. I used to hunt a small piece of timber company land but the neighbor didnt like hunters and wouldn't let you recover an animal if it made it to his side of the fence. He was a real piece of work. We stopped hunting there because it wasn't worth losing an animal.Even if the landowner says no the game warden has the right to check to make sure that there is no wanton waste and also that the deer has been properly tagged. If the guy has the carcass hanging in his garage without a tag the game wardens here will seize the carcass and give it to the person who shot it to tag.