Leslie Charteris sued RKO contending that "The Falcon" was "The Saint", his creation, in disguise. The disposition of the suit has not been discovered. RKO made the change because Charteris had become an annoyance to the studio with his carping about changes in his original stories.
In Leslie Charteris'novel The Saint Steps In," Simon Templar (the Saint) suggests going to a movie to a lady who responds by asking whether they should take in a Falcon picture to watch someone do a bargain-basement imitation of him.
In order to ease the transition from "The Saint' to 'The Falcon' RKO cast Wendy Barrie in the series. Barrie had played the female leads in three of the George Sanders' entries in 'The Saint' series, albeit in different roles each time.