The first cut of the film was considered disastrous by all involved. Editor 'Ralph Rosenblum (I)' worked for more than a year to save it, with director 'William Friedkin' long gone. The extensive use of period film clips was Rosenblum's idea. The technique of returning from these clips to the movie by starting with a black-and-white version of a shot and changing to color was invented accidentally when the editor's assistant couldn't find the color copy of a piece of film fast enough.
Bert Lahr's part was intended to be larger, but the actor died during filming.
Because of the excessive overtime generated by shooting around the death of Bert Lahr, Norman Lear gave gifts of initialed Tiffany silver money clips to many of the crew members, at the wrap party.