The two men in the lounge never see it coming.
In a second, the bomb goes off and reduces them both to a bloody smear.

Hearing the blast, Sean drops down onto the balcony. He can see through the open door that the raiders upstairs are frantically trying to shore up their position around the door they're guarding. All of them have better armor than what he's seen the enemies wear up until now. All of them are carrying shotguns and revolvers. They have not noticed him yet, but they are alert and ready to shoot at shadows.