If you are talking about a pup, you should get in front of him and force it to turn around. They sometimes don't have the experience to determine direction very well and need help. Now if you are talking about an older hound, I've seen very hounds try to go backwards especially when they are tally hoed to a track and they are pumped up and excited. good ones tend to figure out they are wrong quickly and will self correct before going very far backwards. The ones that continue to hammer along on a backtrack never seem to come out of it in my experience and will mess up a good day in the field in a hurry causing many lost rabbits and much embarrassment to the owner. Will wind up eating more feed than a good one does if not culled properly.JMHO
James