Sunday's episode was very good. It was awesome to finally get the prison battle on TV. I think it would have been better suited as the finale to Season 3 when the Governor's people actually had a valid reason to attack. The Governor's story was probably too rushed and under-developed, but that's better than a season-long retread of S3.
I loved the fight between Rick and the Governor, and the end for that villain was very satisfying. I had a feeling Hershel's death was coming, but it was still painful. Daryl being a badass is always fun. I'm glad the tank made it into the show, but randomly shooting buildings at the prison was stupid. The closing scene of Rick and Carl fleeing the prison was perfect.
Carol helped and took the blame? Might explain a lot more of her reasoning for wanting to take the girls with her and out of the relative safety of the prison... She was awful eager and Rick shot it down immediately.
I've really felt she's a far more likely suspect than Bob... Bob I think is just f'd up with guilt. He was mega guilty about Zach but then would lure zombies into the prison? That doesn't jive at all.
I can see Carol being involved but it being a lot more complex than just Carol killed them. It'd make sense, but I'm not so sure the girl is who's luring zombies to the fence and stuff. I dunno. I lean to an unknown source... Remember someone watching Carol outside the fence? I believe that's who was outside being "stalked" and they've NEVER gone back to that, that I can recall.
I'm pretty sure the guy watching Carol during last season was meant to be Andrew, the prisoner who caused all the trouble leading to Lori's death. Bob seems pretty straight-up (aside from the drinking problem), so I'm ruling him out as the killer and rat feeder. I expected him to have ties with the Governor due to the character's comic origin, but that didn't pan out. I'm leaning towards Lizzie as the killer and rat feeder. There are clues like her naming of walkers and playing in Glenn's blood, plus the comic had an interesting arc involving a psycho child which I could see the TV show wanting to adapt.
Also, just something regarding baby Judith...

Is it me, or does it look like Tyrese could be cradling something in his arms?