I don't think any of us expects Hollywood writers to employ numismatists to check their scripts for inaccuracies, but certain thing rub me the wrong way. Are there any coin terms or uses you can think of in movies that don't fit the time period of the setting?
The one that bothers me most is the use of the word "nickel" when the film is supposed to be a western from the 1860s to 1870s. Nickel three and five cent pieces didn't circulate to any great extent in the wild west in the early days. Couple that with the fact that term "nickel" usually referred to early Indian Head cents until the copper-nickel 5 cent pieces became more common, and you have an odd situation when a cowboy refers to a "nickel" in a film supposedly set in the early 1870s. Unless he'd gone "back east", a cowboy wouldn't likely have seen either a copper nickel 1, 3 or 5 cent piece.
On the other hand, it pleased me in the series "Lonesome Dive" to see Augustus McCrae lay two half dollars on the bar when tendering a dollar for two glasses of rye whiskey. Had he taken out a silver dollar in a scene supposedly set in 1876 to 1877 Texas, he would have had a scarce coin indeed!