Bad acting by Cary Grant
Cary Grant just seemed to read his lines off cue cards or something. His facial reaction and gestures are the same throughout the entire movie. He doesn't look in love with Alicia. He is just a handsome man, that's all he was hired for. He didn't make his character Devlin anything rememberable or anything. Anybody could have played that role. At least Bergman tried to act, Grant just showed up to work and read his lines. This movie is over-rated. Grant's performance was weak. Bergman and Grant had no on-screen chemistry in this film.
If CTU would let Jack Bauer do his job, the show would be called 12.