That's the general consensus of what I've read and been told, John. There were other reasons given such as T. Spilotro "fooling around" with Rosenthal's wife, and the possibility that T. Spilotro might "break" under pressure when he went to court. It also seems that his brother, Michael, just got caught up in the goings-on. Michael wanted to be a gangster and the feeling apparently was that if The Outfit hit Tony they would also have to take out Michael.

I believe Aiuppa was quoted as saying something like, " I want them out; I don't care how you do it, but I want them out." Maybe not an exact quote, but close.

There could also be other reasons that I haven't read or heard.