Shooter incident at elementary school in Uvalde, Texas - 19 children and 2 adults dead

I would bet you my savings that all it would have taken is a couple of shots in his direction and he would have wet his pants. He was a coward.
I agree. Regardless of his disposition and/or experience, you don't sit on your hands when you're hearing shots popping off in a school, you go in and breach the classroom immediately. Deal with the consequences after it's all done.

It's my understanding that in an active shooter situation, in most situations, you move immediately onto the shooter's position and attempt to neutralize the threat so that not only stops the shooting and killing, but it also allows EMTs to get onto the scene and administer the aid in time for those who are severely injured and need immediate medical care.