I think the Gambinos should've given Favara a pass. I mean, just look at all the rats they give passes, and the rats don't even have to hide. Seems twisted that they would kill someone for an accident but let others live who sent people away forever, on purpose!
I don't think the Gambinos approved it, or even knew it was going to happen, it was Gotti's closest people and him acting on their own.
