I'm really questioning the Governor's tactics in attacking the prison. Its obvious he just wanted to send a message, they did not attempt to storm the prison.
Breaking down the front gate was a good idea but WTF was the point of loading the truck with walkers? They fit what like 10-15 walkers in there? Is that supposed to make the prison yard unusable? Once they leave ricks group will have the yard clear in 5 minutes.
If breaking down the gate and releasing walkers was meant to be a distraction for another attack it would make sense...But there was not other attempt to take the prison...and they left the truck there, didnt even drive away in it....I guess ricks group will now have a perfectly good armored zombie carrier now.