Other mistake: Issac is on the phone with his boss and he is holding his phone upside down, noticeable because his otter box case is upside down. (00:14:41)
Continuity mistake: When Isaac and Bob Lee are moving from the stairwell to the office they magically go from not having a sight on their rifle to have a mounted (maybe red dot?) sight on their rifle. (00:17:15)
Continuity mistake: When Bob Lee and Isaac are in the firefight in the office building, the bullet holes in the walls change position or disappear.
Revealing mistake: When the sniper is aiming at Swagger and the soldier through the window, a woman walks in and notices him. He shoots her and she falls. The problem is, he shoots at nothing. She simply turns her head and acts like she got hit. There's no indication a bullet even hit her.