She's comparing the cases
One did know someone behind the door, one didn't.
One fired one shot, one fired four
one had aim to frighten away intruder, present case aim to shoot intruder
One case had opp to flee, present case opposite is tru, Intruder wld have had no room to escape
present case accused trained in firearms and intended to be a collector
The degree of negligence in this matter, sentence suggested by AV not appropriate.