Goodness I never thought of Michonne, good observation. Come to think of it out of all those on ground i noticed Rick and Maggie were both like they were about to turn into a raging zombie. Like a panic attack times 10! Also could be from the shock of what's going on inside her. Also the cutting of her hair all of a sudden. She's going to be GI Jane in this! I think she's going to make Carol look like a Saint.And another thing that points to Glenn is that the first scene of the episode, just as the last scene, was from a first person perspective. There was another shot from the same POV sometime during the middle of the episode. It's a premonition of things to come. They weren't placed there by accident. One could argue it could be also Rosita or Michonne, but I think Rosita's death wouldn't be as devastating. I suppose my guess after Glenn, would be Michonne. I do think they intend Maggie's and Rick's demeanor to really change next season.
Carol was changing but saw how Maggie was changing into Carol. Head butting, beating that smoker lady. She's gonna go ham if it's Glenn. If Michonne dies Rick might as well be the leader of any group. He will kill all them like he tried to solo all the zombies at first.