I wanted to post this in an active thread, I feel this question is related enough: Godfather Legacy is on right now on the Reelz channel and I'm watching it snowed in.

Say Roth had succeeded and gunned down Michael in his home. Would have reason to fear reprisal from the Corleones? If history is any indication, that's about 300-500 made men spread throughout America. Would he fear reprisal from other families on a matter of principal? Maybe Roth was counted on misdirection. Nobody would expect the semi-retired Jewish gang boss of Michael's murder, and he could quietly take back his casino rackets.

I enjoy the theory, posted here once, that Ola was a renegade Corleone capo who forgot who his masters were.