Continuity mistake: When James Coburn is about to leave the phone booth where he's been lighting matches, the number of matches he leaves on the top of the phone changes between shots.
Continuity mistake: Charlie's fingers, when he is dead, change positions when suspects arrive for his funeral. (00:17:00 - 00:19:00)
Continuity mistake: When the French inspector is interrogating Audrey Hepburn, he asks "Why did he want to leave France?". The shot changes to the back of the inspector and Audrey replies, "Leave? No." Then the inspector makes a rough movement with his body and head to his right, but the movement is brusquely cut and replaced by a front shot where he is sitting perfectly still, as he was doing in similar previous front shots.
Continuity mistake: Towards the end of the film, 'Adam' meets Reggie at the meeting where she is working as a translator. They hurriedly leave for the venue (gardens) where her late husband had his last appointment. She leaves her friend, Silvie (who has several appearances throughout the film) also working there as a translator. Yet no sooner have they arrived at the gardens than Reggie sees Silvie sitting on a bench reading a magazine, waiting for her son to return from the stamp market. How could she possibly have got there so quickly?
Continuity mistake: In the bedroom, Cary Grant puts on his glasses to read a note. When Audrey Hepburn says "I love you, Adam", he turns around and doesn't have his glasses on anymore. Next shot, they're in his hands. (01:25:20 - 01:26:00)
Continuity mistake: While Cary Grant and Audrey Hepburn are on a boat going down the Seine, they have two drinks in front of them on the table. The problem is: the drinks keep changing, from full, to two-thirds full, then back to full again, both of them, over and over.
Continuity mistake: When Cary Grant and George Kennedy are fighting on top of a building, Grant is hanging over the edge, but the rooftop sometimes has a metal framework on it and sometimes it doesn't.
Answer: Blowing out the matches would only incite Tex to act even more aggressively and threateningly. Reggie knows he is not intending to hurt her and only wants to frighten her so she will cooperate in finding the money. Even though she is scared, it's wiser to remain as passive as possible.
raywest ★