Are you sure he's not quiting the track and back tracking his way out instead of making a loose and taking the track backwards ? I'm in no way form or fashion being a smart a$$.
I think this is a good and honest question. It would be easy to believe a dog may be running the back trail when in fact, the dog quits running th track and runs back on the same traal he came in on. The answer to this question would probablt be if the pup stays on the back trail past where he started it.