Other mistake: The opening credits for season 5 show June coming out of the front door with a pitcher of what looks like iced tea, and calling for Ward, Wally and Beaver who are all working outside. But the door opens by itself as she comes out, and then closes by itself behind her. If the entire family is outside, who opened and closed the door?
The Case of the Sausalito Sunrise - S9-E19
Other mistake: The owner of a Los Angeles trucking company tells a driver who is going to San Francisco, "Take the San Diego Freeway toward Bakersfield." That freeway runs from San Diego to San Fernando. It does not go toward Bakersfield.
Other mistake: As the 2 buffaloes are walking out of the scene at the top of the hill Charlie says to Clyde that 'it's either gonna be her or me' but as both buffaloes' bellies are exposed in the same shot, it's clear that both buffaloes are males, or bulls.