Before you posted that the hands are white i had a feeling it was Bob. Bob was found on the road by Daryl. He could be the one that spreaded the virus and feeding the zombies. Why? Not beacuse he drinks (that's to forget his sins) but maybe beacause his wife or son is held hostage by the gov in order to make sure he sabotages the whole prison. IWhy isn't he sick? Or maybe he has seen some horrible stuff back at the other 2 camps (canabalism or something) that completely made him insane. I mean isn't it weard that an alcoholic, that is not really a fighting machine like Merle could survive the extermination of 2 camps?