It's all the black helicopter's fault! The opening explained a lot...still some plot conveniece that they wound up that close to the farm, but it's fiction.
Jimmy saved Rick and Carl and that's the thanks he gets.
There's really no reason to assume the heard won't move away from the farm sometime. They can go back raid the canned goods. No?
Going back to the highway was a nice touch, full circle...a grim "right back where we started and worse off".
Andrea was almost in the clear except for that last walker. "Yeah, you saved me...waited until there was one left and I was exhausted...thanks, grim reaper samurai."
Rick explained himself...poorly. He should've said he thought Jenner was mental. Also, that Shane was gonna shoot him.
Speaking of infection, Maggie has been infected with the dreaded Lori virus, and will now undermine the group's cohesion at every possible moment.