It is painfully obvious that you don’t have a clue about canine handling. It might be best to post on something you are knowledgeable on.
When dogs are sent on pursuit, they are taught to bite, take the criminal down, and hold until the officer catches up. If it gets to the point that the dog is sent on a pursuit and bite, it nearly always ends up this way. No way to reliably prevent it once the dog is sent. You seem to want to recall the bullet once it is out the barrel...
This kid/criminal had to spend three days in the hospital because either: 1. The dog was not trained properly or 2. The officer handling the dog was not trained properly.
The whole point of the dog is that it obeys commands - as such it is EXACTLY like recalling the bullet once it is out of the barrel - if handler and dog are trained properly.
a bite is one thing, 3 days in the hospital is something different and not the end-result desired under any circumstances from a police dog.