Let's see if I can wring an answer here out of Apple first, otherwise, I will.

I think it will be hard to start a thread based on the premise that if Fredo had disagreed with Michael in public twice that would have been grounds for killing him.

Who is gonna agree with that?

And I wouldn't expect anyone to agree either that Sonny should have been killed on the same basis - two transgressions, albeit more serious ones with more far reaching consequences than the hypothetical Fredo scenarios.

I don't see much of a discussion here, to tell you the truth.