Episode #1.8 - S1-E8
Stupidity: There's a gunman that just opened the school doors, and he's looking at the police like "a deer caught in the headlights" and they are all pointing their weapons at him and he's holding a gun mind you, but somehow these cops let him run back into the school without even taking a singe shot at him. His background was clear too, so if the cops fired there would've been no collateral damage if they had a shoot out. (00:35:00 - 00:35:30)