Well, it was more like a realistic one in this case. Someone waits till their victim is taking a piss, then shoots them repeatedly at point blank range....
I'm a bit confused as to your insistence that pros, a SWAT team or whatever, would behave this way. I'll paint what I would see the equivalent scenario would be:
SWAT team are dispatched to a house as a neighbour has phoned in saying there might be an intruder in the house next door. However no intruder has actually been seen so far. They are told the home owner is in, so there is definitely at least one innocent person in the house. They arrive on the street, collect a spare key from the neighbour and quietly let themselves in to the house.
As they walk down the corridor in the dark they hear noises from behind what looks like a bathroom door. So, obviously, they open fire at the door without further ado. No challenge of the person behind the door (no checking it is even a person), no checking first where the homeowner might be. Blat, blat, blat into the door - maximum force.
They open the bathroom door and, quel surprise, the homeowner lies there full of holes. Not only is the homeowner dead, she is also, horror of horrors, white, blond and pretty. No intruder exists.
Now, I don't know about you, but if I heard about this incident, I would be expecting that particular professional to be going to jail for a long time.