Castellano certainly wouldn't have believed that his days were numbered, even if they were. I'm sure his lawyers told him he could beat the Commission rap because RICO hadn't been tested on that scale previously. Ironically, one of the reasons that most of the other families didn't object to his assassination was that they feared he'd turn rat rather than go to prison and be away from Gloria Olarte, his beloved Colombian housekeeper.

With Neil Dellacroce, Gotti's protector, dead, Gotti's crew about to be disbanded, and Tommy Bilotti named underboss, Gotti had good reason to think that his days on the street were numbered. It was kill or be killed.