I have no contact what-so-ever with the first owner so heaven knows what type of a man he was.
I've only contacted Vega's first owner once, to ask her if Vega was tested for hypp. She didn't seem the least bit concerned about it, nor did she seem concerned that her horse was now living in NJ(she was originally from Wisconsin I believe). I had sent her recent photos and haven't heard back from her since. Some people I guess just don't care where their horses are now or what's going on with them. I wouldn't just to conclusions with his first owner.
Blu-i used to ride a pony that would canter down hill, even on a flat straight surface, so i'm guessing it is possible. But I think a horse could also appear downhill when moving if they are heavy on the forehand.
Sonny-is there a way that you can lunge him in a round pen, or have him on a lunge line? You might be able to see if he's short stepping because you'll be able to control his gaits a bit more. Unless he is voice command trained. See if you can get him to trot instead of just cantering around.
Correct me if i'm wrong, but isn't any sort of lameness or stiffness more prevalent in the trot than at the walk and trot? Isn't that why when the vets to lameness exams they make the horse trot, instead of walking or cantering?