When Fred and Barney area heading off to the race, it's nighttime. Then, when they stop at the payphone to call Mr. Slate, it's daylight. In the next shot it's nighttime, then in the next shot it goes back to daylight.
After Bamm Bamm closes the door after going outside with Pebbles to play, Wilma compliments about Bamm Bamm and Betty wishes Bamm Bamm would be more careful with the door. After Wilma says "He means well," her eyebrows disappear.