Yep I agree Sonny Black the murder of George from Canada set the split in motion. It was said they were splitting from them even before then as George showed more loyalty to the Rizzuto's than he did the Bonanno's and rightfully so being where he was from. Of course that cost him his life too.

I also think the Rizzuto's figured out the USA was nothing but trouble with the RICO laws and that is another reason they were splitting from New York and when they hit George it pretty much gave them their reason to snub New York. I don't think for one minute they are still under NY control and haven't been for a LONG time.