Gravano and Castellano were close, and it was a sure bet he would come to Gotti's aide. Why? It was a one sided friendship really. Castellano started more or less hitting on Sammy when he heard Gravano was moving in to construction. From then on Sammy accompanied Paul on important business trips with the obvious addition of Bilotti. That was one thing that made their relationship even more bizarre. Sammy absolutely HATED Bilotti, and Paul never went anywhere without him. So anyway, put all this together. John and Angelo Ruggiero, leaders of the dissident faction were people persons. I'm sure they observed how close Paul was to Sammy, yet how distant Sammy was to Paul, and knew it was an easy move to get a guy with a lot of reputation for keeping a loyal crew and having plenty of muscle. That's something people forget. Sammy had Huck Carbonaro and an assortment of loyalists. And here's my favorite line from Underboss to sum up how Sammy was feeling about Paul at the time (paraphrased)
"Word is, Paul was gonna make Tommy Gambino Acting Boss and Tommy Bilotti the Underboss. First off, Tommy Gambino is a fucking dressmaker. I was down in the garment district one night and ran in to him. He was sewing up a lady's dress and says "Sammy, does this look right to you? Does this dress look right to you?" And Tommy Bilotti is an abusive Gorilla."
