Man, I hate to hear that but it does happen. An uncle of mine once shot a deer with a 7mm mag and thought he had a solid hit.While tracking it, the deer would run about a quarter mile and lay down, leaving a pool of blood. Every time he would get close it would jump up and run before he could see it, he would just here it run off. After tracking all day for about 5 miles he finally decided the deer was probably going to live despite all the blood it had lost. It's not what we want to happen but it does. Good luck on the rest of your hunt.