Whoever was banging on the door (and he would have to know that it was somebody trying to get out) may well be dead now, and that's on Burbano's conscience.
Holding the door closed until your group can get safely away and locking it after you are two very different things, though, and people will judge those acts differently.
Correct. We really need to wait a bit to verify which of the two it was. If he was holding the door shut with a possible shooter on the other side, he was a brave man. There was a professor named Libresku at Virginia Tech who did that to protect his class and died for it. On the other hand, locking the door when he knew others were trying to use it to escape is a very, very different matter. Either way, it was ugliest for the people inside.