Don't know what you could've done. I do think it does matter if he wounded the deer with the first shot though. In my opinion if he felt he had,he is then obligated to try and finish it off. Up to the point you explained, I feel like he did what he could short of learning to shoot and staying in his limits. I further feel his next action should of been to contact the owner of the ranch. Let him know what happened and ask for permission to enter property and check for blood and perhaps recover deer. But all he can do is ask, it's the owners decision to make.