The door knob stuff is a bit tricky.
First off the lock shouldn't have been there. The game clearly states that the room has no lock.
It also defeats the purpose of the lock Oogami created.
As for the rule break you can explain it with the loophole this rule left:
Thee rule only prohibits you from
destroying the
door.
So you can get several loopholes out of it:
- It is not forbidden to bypass the lock
- It is not forbidden to damage the door as long as it is not destroyed
- The door's window is not counted as part of it and can thus get destroyed.
Either way the door was never really destroyed or broken down. In fact he damaged the window to be able to open the lock that should not have been there in the first place.
Admittingly pure speculation, though the only way to justify that lock
