Factual error: In one scene a parked car is sitting along the street - it is a '68 Chevy, it has sidelights. Yet the film is set in 1962.
Factual error: When Hooker comes out of the diner there is a billboard advertisement to the right. It is for Ezra Brooks bourbon. Ezra Brooks brand wasn't created until 1957.
Factual error: The oil "drill" is actually an oil rig, meant to pump oil, not drill for it.
Factual error: When Olive is repeatedly saying "I can't find it," Mr and Mrs Briggs are listening through the walls of their bedroom. However, we can see when Jack and Stan return with the toilet that Mr and Mrs Briggs are staying in the chalet to the right of the Butlers. When Stan first shows the family their chalet, it shows that their bedrooms are on the left. This means they wouldn't have been able to listen to Arthur and Olive through the wall.
Factual error: When Webster is attempting to open his first safe, on the job, so to speak, he only turns the wheel once. Now, I am not an expert on safes, but I do know that the wheel must be turned back and forth, with the correct numbers, a few times, at least.