After Mathews comes down the hill and confronts the gem thieves, he pulls his gun and shoots the thieves car tire. The tire shot is a black wall the thieves car has whitewalls and different hub caps. When the undercover police car drives up, Mathews, who JUST shot the tire is nowhere around.
As George Haley and dog pull into the Station to catch the train to Mexico, the reflection of the boom mike is clearly visible in the rear window of his 1957 Ford Sedan.
When Mr. Harris is speaking with Mr. Haley there is a boom microphone and Light Box reflecting in the window immediately behind them to the left. When he is backing out the entire boom microphone is visible in the windshield as he backs up.
When Dan Matthews is talking to Dr. Corbett in his workshop at his house, a shadow of a boom microphone is clearly visible on his white lab coat.