John Laroquette was John Candy's first choice for the role of Elliott Draisen, because the two had been friends since working together in "Stripes" (1981) eight years earlier. However, Laroquette was busy with "Night Court" (1984) and couldn't accept the role. Candy's good friend and frequent collaborator, John Hughes, then suggested Jeffrey Jones for the role, as Hughes had directed Jones in "Ferris Bueller's Day Off" (1986). Candy initially was hesitant because he felt the film would seem too much like a John Hughes film without the involvement of Hughes himself, but Hughes assured Candy that Jones was right for the role and he was cast.
One of John Candy's major grievances with the finished film was TriStar's abysmal marketing campaign in the spring of 1989. Candy had gone through the trouble of preparing an ad campaign and handed it to the studio, but TriStar executives rejected it, saying they had their own. According to Candy, there was very little evidence of it. "I had to rent my own billboards", he complained incredulously afterward. TriStar purported not to believe in billboards. Obviously, TriStar had lost faith in "Harry Crumb" before it was released and opening it was just a matter of going through the motions. After only a few weeks, the movie was pulled from theaters.
Director Paul Flaherty and actor John Candy were alumni of the Canadian sketch comedy improv troupe, The Second City, whose work is anthologized in "Second City Television", later "SCTV Network 90."
This was the first of four movies starring John Candy released in 1989. The others were: Allein mit Onkel Buck (1989), Cannonball Fieber - Auf dem Highway geht's erst richtig los (1989), and The Rocket Boy (1989).
This is the third movie of the '80s in which the song, "Holding Out for a Hero" (1984), by Bonnie Tyler, was playing during an action sequence. The first was "Footloose" (1984), when Kevin Bacon is playing chicken with Jim Young on a tractor; the second was "Short Circuit 2" (1988), when, during the climactic scene, Johnny 5 the Robot is chasing and fighting bank robbers before they escape; and in the third, "Who's Harry Crumb?" (1989), John Candy chases after the kidnappers before they escape, similar to "Short Circuit 2" (1988).