The only shared credit of both actors who comprised The Thing with Two Heads (1972)--Ray Milland and Roosevelt Grier--other than the original cult horror film.
The third of three shared credits of Helen Hayes and James Caan, for each the son of whom would play the same character in two versions of a classic long-running CBS cop show, with Hayes's son James MacArthur originating the character of Danny "Danno" Williams on Hawaii Five-O (1968) (also reprising the character as becoming the governor of Hawaii in the TV movie update Hawaii Five-O (1997)) and Caan's son Scott Caan playing that "Danno" role in the reboot series Hawaii Five-0 (2010). This was the only one of the three events where MacArthur also attended. It should be noted that if the two sons had arranged for each parent to get the gig, the proper phrase would have been "Book 'em, Danno!"
Thirteen years earlier, three of the stars in attendance--Charlton Heston, Jeanne Crain and Roosevelt Grier--had been co-stars in the air disaster flick Skyjacked (1972). It remained Crain's last acting role, this special being the only other shared credit among the three actors. Another of the main actors in that film, James Brolin who was not in attendance this evening, would later portray the guest of honor Ronald Reagan rather unflatteringly in The Reagans (2003).