‘FAMILY GUY’S’ 9/11 SATIRE , Show reminds that MacFarlane partied his way off doomed flight.On Sunday night, MacFarlane satirized the Sept. 11 terrorist attacks a decade after the plane he was scheduled to be aboard was flown into one of the Twin Towers. The episode of “Family Guy” — the cornerstone in MacFarlane’s animation empire — was a dark reminder that had Fox’s future multimillionaire creator-producer made it to the Boston airport minutes earlier, he wouldn’t be among us to lampoon those very events. On Sunday night’s episode, baby Stewie and Brian the martini-sipping mutt use a time machine — employing clones to carry out the tricky business of monkeying with past events — and grapple with the opportunity to prevent 9/11. Their ultimate moral dilemma: Alter the course of history or let it go unchanged?In a nod to self-parodying the show’s origins, the episode is titled “Back to the Pilot.” (Although given the show’s twisted sci-fi democracy, the episode could have been subtitle...