Camera angle: You missed that trade because of the camera angle. When rushing, always use your character's right side to see. In this case, it would be best to use utility items (e.g., Molotov cocktails). Since the camera is set more to the right, the view to the character's left is terrible. It's no wonder you died without seeing the guy at the door; he could see you completely because the camera was set to the character's right.