Myself, I understand how the guy felt. You don't want kids to think you went back on a promise -- not one of THIS magnitude -- or that you're a loser. But really, the guy needed a LITTLE more forethought for the project. As in: ask Disney to re-book you for a cruise NEXT year, and stop buying smokes or something to make sure you hit the new date.
Now the GF and kids KNOW he's a huge loser. And he'll have a damn hard time living it all down with the folks he'll meet in prison.