Boot camp for a 14 week old pup??? Is this common? Well, I think whoever did this to the pup ought to be shot! This MAY correct itself, but I think the chances are against it. The ligaments that hold joints together are NOT elastic. Once stretched, they stay stretched. I'm speaking here from my knowledge as a nurse, personal experience with bad ankles, one of which required two operations, and many years of working with horses. YOU DO NOT JUMP horses until they are fully mature at age 3 or 4, not unless you want to ruin them. Yes, they do race horses before that, but that is not as high-impact a sport, and the rate of injuries is very high.
We would see fewer horses break down if they weren't raced until 3, but usually the almighty dollar prevents that from happening.
The pup may have been genetically predisposed to this. It's unfortunate, but I think the owner would be better off to start again with another pup.
I also had a friend with a dog that had one dropped pastern, the result of jumping off the porch after a squirrel. It never corrected itself, but the dog was full grown when it happened.