I shot a 3x1 two years ago, his spike side was about ten inches long or so with now evidence of trying to branch. I looked into it, reading articles about antler growth and asking around and I came to the conclusion that he must have damaged one of his testicles before his horns started to grow, I read that the opposite side of the weird horn was the one that was damaged. There has never been a buck in the area with horns like his, I have hunted that area for seven years and between my dad and I we have taken many nice deer out of there but never one like that one. Maybe the buck you saw had something along those lines happen to him.
My dad also shot a a 4x1 about four years ago and he inspected the deer to find that he did indeed have a abnormal testicle, like it never descended down like the other did.
Just thought this would help
