Personally, my opinion about Michael killing Roth can only be identified by digging into his character. For example, the way I see it, A heroic character is one who is weaselly with no backbone---let's call that 'morally weak.' Does anyone deliberately act weak? If that was a no, then we'd have nothing but heroic characters and nobody to be a foil. In short, other kinds of story where twist is everything and character doesn't drive the story would mean that Michael would somehow gain that knowledge through the character developement. I do not believe this to be the case! the simple facts are that Michael is a rapacious character. This should tell you something about his grandstand! Michael would definitely still asphyxiate Roth in the upshot.