5. Not Keeping Track Of Carl
Maybe this is Lori's fault, but I'm going to go by the rules of executive responsibility, because Rick wanted Carl to stay in the house too. Obviously, Rick has to keep a lot of plates spinning that's par for the course. Yet still, keeping track of your own flesh and blood has to be up there with the most important of those plates. All it would have taken was a word with everyone on the farm that regardless of what he says, Carl isn't allowed out the house. Half the farm group actively live in there anyhow, so it couldn't have been hard. Everyone just assumed Carl would do as he's told, which baring in mind the kid's track record as an idiot, his clearly psychologically damaged state (he's a kid in an apocalypse, after all) and just pure old pre-teen rebelliousness, was a pretty astounding oversight. Hell, maybe after he flouted these wishes for the umpteenth time, they could've locked him in his room as a punishment. I know it's a desperate punishment, but when the alternative is to let him wander off and potentially get eaten, I think forcible grounding is probably a good idea.