Don Tommasino was nowhere near that car rigged with the bomb?

I think Calo, the other bodyguard, was killed in the bomb explosion in the novel but not in the movie [Calo was in Godfather 3]

Was Michael going to Don Tommasino's place?
I suppose Michael didn't go to The Vitellis with Apollonia thus removing himself, the target, similar to leaving Tahoe after the shooting

Fabrizzio had made it known in no uncertain terms, he was desperate to get to America