Don't know why people think "Oh, he's ex-military, so he must be good at killing"
Most people in the military are, for the lack of another word, "Dumb". The entire thesis of military organisation is for you to follow the echelon, you are doing what you were told, most of the people who join the military is not the brightest of mind, and they join because there are nothing for them to do, and the military have a very low bar for anyone to join, as long as you aren't a loner crazy type, you are welcome to it.
People mistaken being well trained for smart, being well trained and well drilled looks smart because you can execute your move almost immediately and flawlessly, because training for a specific scenario means you can deal with that scenario almost instantly, which it looks smart, but is probably be dumbest thing you do, because if the things you are dealing with is altered by just a little bit, then that particular training won't applies.
Planning and execution means a lot of decision making, this is not something a normal grunt good at, On the other hand, law enforcement is not exactly stupid, they also know their stuff, major reason why this incident did not blown up to what it was supposed to be is because of the reaction of law enforcement, they aren't really just sitting in their squad car eating jelly donut..........