This is an engine limitation in Source. Source generally does not know what to do when an object is wedged like this and will keep trying to wedge it further into the wall with rotational force instead of just pushing it away from itself, which produces these results. It also doesn't help that the object in question is a huge player hitbox that does not rotate in any way. Ordinarily any prop placed there would spin around and unwedge itself.
The real solution to this is to make the door open outwards, preventing it from trying to squish anything behind it.
People use that room to be annoying when being chased by cops, since cops can't exactly just wallbang and end the nuisance.