"More than just Lincoln's tragedy...."

[LincolnToddFan]

It's only speculation, but given the layout/confines of the Box and human nature it makes perfect sense for Rathbone to have seen JWB out of the corner of his eye and frozen. It was dark and it's entirely plausible that he did not realize what was going to happen until it was too late. Booth was a celebrity. How could Rathbone have known that he was there to kill, and not simply to have a word with the president?

I've always felt badly for he and Clara.