Yeah, they'd got groups of three dudes sweeping the rooms while some other guys watch the hallways to cover their asses. Standard stuff.

Where things get non-standard is when the troon fires her weapon and gives her position away. At that point, someone makes the call to pretty much throw caution to the wind and race toward the noise at full speed. That was a big, ballsy move - if the troon had moved between bursts of gunfire, they absolutely could've found themselves running right past her and getting lit up from the side or behind.

Lucky for them, the troon seemed to be retarded and appeared to be taking pot shots out of the window while waiting to get shot in the back. Perhaps she didn't have the balls to go up against someone who could shoot back, and so decided she'd rather not see the shots coming. Or maybe she'd deafened herself with her own gun to the point that she honestly didn't hear them running up behind her shouting.

Those cops had balls of steel to rush like they did. Rex wasn't even particularly fast on the trigger - if she'd been waiting, aiming at that hallway, she'd have shot him first.