I was happy with a few things I picked up from that last episode that some other people picked up.
I was wondering for a bit what the point of showing that lone walker shane was looking at in the fields was, and then I realised it sort of symbolises shane himself. first time he sees it he probably thinks it's a good thing, being alone in the world, but probably changes his mind after the events. if rick had treated shane like shane wanted rick to treat other people, shane probably would have died. being alone isn't the best way to be.
the other thing I noticed was the noises the two were making when they were fighting. at one point they were almost indistinguishable from walkers, showing that they can get as savage as the walkers.
I thought there was something else subtle that I picked up, but I can't really remember.