Alright, seen it now, and as far as I'm concerned, Rick can go to hell. His humanity has taken leave of him. He really has become far too gone, just like Morgan. What he did on that highway ignoring that poor straggler completely disgusted me. At this point he's no better than the Governor.
As I recall, Carl, Michonne and Rick had the opportunity to say something, but none did. If there is blame to be passed, it's for all three, not just Rick