It has been suggested that the shots were angled downwards, or even through the lock and hinges. That could contradict the suggestion he was shooting to kill.
It could probably be argued that if you thought there was an armed invader in your bathroom, that posed a very real threat.
The ballistic evidence really is going to be key here. Although firing multiple shots towards a very small space you'd have to be a hell of a shot to pull that off without causing serious injury. I'd have thought, if you were firing to scare, then a shot into the ceiling would be pretty effective.