Just think of this. I play airsoft and have 2 full size, highly identical rifles.
Ok so I take my... AK47, this time. I go to my school and point it at people, then I put a kid in the closet and run away from police, resisting arrest. My local authorities try to talk me down but I refuse. So they bring in the S.W.A.T. team. They continue to try to talk me down but I do not respond or want to be talked down.
Now my dad tells them I'm only 14, and I have a few airsoft guns, so the gun may be fake.
So they are looking at me with guns raised, obviously. I then proceed to point the gun at them.
You think they are going to shoot me?
If they did it was justified because I took a hostile action towards them. What if I did have a real AK-47? What if I held down the trigger? There goes atleast 2 people in the general vicinity, others wounded.
EDIT: What if they did exhaust all of their options. I doubt they just ran in. I am thinking this is the type of bathroom that is somewhat open, where you can see inside if you stand at the right angle and such. Maybe the kid came out? Ever think of that? What if he came out and brought the gun up and aimed it?