If this was written into a film, it would be called unrealistic or far-fetched.
This unstable individual (the cop) thought he'd just lay down and wrassle with a juvenile with no arms or legs.... I'm sorry but that's hilarious and disturbing in equal measure, really, like a crass sketch in a for-shocks comedy movie.
If that's not enough, he then goes on to slam the other cuffed teen's head into the wall because he felt like it.
Something like this goes civil courts in America, right? This cop won't even be fired for this?