Summer Holiday (1963)

Plot hole: When the gang go out for the night, Don tells the girls that they have 30 minutes to get ready, but there is no way that Mimsy (the blonde one from the singing trio) did her hair the way she does in 30 minutes, plus got dressed.

Plot hole: When Mr Wrightmore shows up at the gang's hotel room to tell them that Mrs. Winters is having a press conference at 6pm, Don rushes out in order to talk to Barbara and Mr. Wrightmore seems to know what her room number is. But how did he gain that piece of information? Barbara's mum wouldn't have told him the number because she would then know that he would tell the gang, since he is seen standing with them when they arrive in Athens and he says that he's going to get them out of trouble when the police arrest them under Mrs. Winters's orders.