The building is an old warehouse, so it's got overhead walkways, and catwalks and several smaller work rooms. When I wrote "As soon as the light vanishes from sigh" or something like that it was because all the decoys moved into the building and they closed the door behind them. Yes, they were using decoy slaves. Also, I always pictures the way up the the warehouse overgrown so they wouldn't have to go in to the open,and could do the actual ambush inside. Also, if they are shooting walls and stuff, there no way to say they aren't shooting the slaves inside so I wouldn't see him risking that. But that's you're call if you wanna shoot the building itself. The "Slaves" are being held in a big room on the inside, so they would have to go in anyways and deal with those guarding the "Prisoners". If you attack outside, the prisoners maybe mowed down before you get in there. (I watch too much TV :P)