I can't stand Chris but I am kind of with him on the original cause of the argument, before his defensiveness made it worse. He was asked if he envisaged the future and gave what he thought was a nice idea of what it could be. I don't think he thought it was set in stone. Sam took offence tho.
Chris' nastiness when Sam tried to discuss it afterwards was unpleasant, but he has apologised many times and Sam will not let it go.