Forum:Super Marcus Sweep

Hey guys, I've been using this site for awhile, but I haven't posted anything as of yet. Right now, I'm asking for help, because it seems while doing the quest "Super-Marcus Sweep," I glitched through the floor (which I meant to do), but the blast doors shut and the game checked off the "steal loot" box. Now I can't complete the mission or farm the armory.

If anyone on the 360 can help, add my GT NoelarExpress, I'll be online around 11pm eastern time tonight (3/2/10)