At about 38 and a half minutes into the movie, while Angela Twitchell and her mother are talking in the bedroom, her father's shadow can be seen standing outside the door for more than 15 seconds before he actually enters the room. This means that he should have heard their discussion, thus learning that his daughter is the saleswoman for the competition.
When Pat and Claudette are flying in the biplane, the pilot announces they are over Chicago. But, many hills and even a snow-capped mountain can be seen in the distance. There are no such topographical features near Chicago.
When Angela and Pat walk away from McNeil's office door, a moving shadow of the boom microphone is visible on the wall behind them.