When he is locked in the hospital room and breaks out the guard uses a key to lock the door, when he breaks out he uses a slide type lock to open the door.
In the lower level OR, after Ray shot an oxygen tap and shot once more in a overhead lamp, there is an explosion coming from the oxygen circuit.
Oxygen does not cause explosions. A rich oxygen environment would only make any combustion quicker.
At no time do any of the hospital staff react appropriately to a confused patient with a possible head injury.
Emergency rooms triage patients.