Lethal Weapon 2 (1989)
Michael Kamen's track "Riggs Dying", and Eric Clapton's cover of the song "Knocking on Heaven's Door", were composed and meant to be used only in the "Riggs Dies" ending, so George Harrison's song Cheer Down was used for ending credits, once the "Riggs Lives" ending was chosen for the final version of the film.
Boam had to do the same with his script for Lethal Weapon 3 (1992) during filming of that movie. Another screenwriter, Robert Mark Kamen, mentioned in a 2012 interview for craveonline, how during the time when he was working as a screenwriter for Warner Brothers, and would often do lot of uncredited work on their films, he also worked on Lethal Weapon 2 and 3. He said how amongst a lot of the stuff he added in the Lethal Weapon 2 script during re-writes, were all the parts with the South African villains. Although he was uncredited for his work on this film, he did get a credit for his work on Lethal Weapon 3 (1992), because he did lot more work on that sequel.