I'm actually half-serious here:


Say Michael knew that Tom went "undercover," but the reason he really did it wasn't the reason Michael thought it was?

Tom chafed under Sonny as the Don because he thought Sonny was too wild and unpredictable - how would he react to find that Sonny's son Vincent, if anything even more hotheaded than Sonny, was now in charge?

And since he himself had been the consigliere, the "guiding force" behind the family, the "voice of wisdom" dating back to Vito, how would he react to the fact that in effect Connie had now assumed that role?

Sure, Tom spending 18-20 years in hiding and then just deciding to return one day would seem a litle far-fetched, but certainly no more so than an unheard-of bastard son of Sonny just appearing out of nowhere....