You have to look at it in context. We had run out of food two days before this. The rain was keeping us supplied with drinking water, but we couldn’t go without food for much longer. Most of us figured on going out, scouting for canned food in the supermarkets before we were too weak to make it.
Warren wouldn’t have it though. Said we’d get ourselves killed, and even if some of us made it back with supplies, we’d just be leading the undead hordes back to the safe house. Said he wouldn’t allow it.
So we ate Warren.