The best way to tell if a gut shot is with your nose. Go to the point where the deer was hit and start sniffing. Did you smell the deer after the shot? Don't confuse the tarsel smell with a gut shot smell; the gut shot smell is much stronger, and in some cases will allow your nose to lead you to the deer. Problem is that the deer will live long enough to outpace you even if you wait a half hour, and then you had your snow conditions. Also the other animals come to the gut shot deer quickly, using their sense of smell, so he may not be in tact when you get to him. Finally, a gut shot deer heads to water as it feels thirsty.