Burt Reynolds's underweight, weak and thin look was because he was still suffering from the effects of an accident that occurred on the set of his previous movie City Heat (1984). His jaw was broken when he was hit in the face with a metal chair while filming a fight scene. He was restricted to a liquid diet and lost over 30 pounds by the time that movie wrapped. Apparently this accident led to Reynolds becoming addicted to painkillers.
This movie was originally set for release in August 1984 but Universal Pictures demanded that director Burt Reynolds shoot additional action scenes--at a further cost of $3 million--and cut down the film's humor to make it more commercially viable.
Final theatrical featured directed by Burt Reynolds until The Last Producer (2000), a gap of fifteen years. That movie was not theatrically released but during the interim Reynolds did direct in television.
Elmore Leonard, screenwriter and writer of the novel upon which this film is based, apparently disowned it after Universal Pictures ordered extensive re-shoots. Leonard was very critical of star/director Burt Reynolds for what Leonard perceived as Reynolds' not fighting Universal hard enough to prevent the studio from doing it.
The trivia item below may give away important plot points.
The death of Moke, the albino hit-man, played by the late stuntman Dar Robinson, sees him fall from the side of a high-rise city tower whilst firing a gun. This stunt, of note in film history, was filmed using a device known as a "decelerator". This device, which was invented by Robinson, allows cameras to film from above with the use of drag-line cables that replace the usual landing airbags which would be visible. Robinson designed and performed this incredible stunt where he was rigged to a complex wire rig that "deccelerated" his fall and made the use of an airbag unnecessary.