I found it amusing that the zombie drug had the street name devil's breath. As though zombie drug wasn't quite bad ass enough.
I felt for Carter. He lost his girlfriend in one of the most horrific ways possible and will always question what really happened that night. The blanks in his memory will surely drive him crazy for years to come.
Did the two woman really need to kill his girlfriend when she found them robbing him? I suppose that's a silly question. Does anyone ever need to commit murder? It just seemed like they could have made a run for it and if they'd laid low for a while, they might have gotten away with it.