No matter what the problem between Gotti or Gravano was, they should have stuck together during the trial. What they did to each other was exactly what the FBI wanted. Maybe they would have gotten out of trouble (I emphasize on maybe). They could have dealt with their problems after the trial. They could have sat down and discussed their problems, if they were really as close as they said they were.

People can change!
"A f****in jerk like me. Never had nothing in my life. That's not John Gotti. At least I hope that's not me. Maybe I see myself in a light that I'm not in, I don't know."-John Gotti about greed
"We only kill each other."-Benjamin Siegel
"There's no such thing as good money or bad money. There's only money."-Lucky LucianO
R.I.P Mr. Gotti