I saw a mediocre movie about Walt Disney once (not authorized by the Disney company or I think even the family). It was fairly low budget and one of their selling points was having the star of Napoleon Dynamite in a minor role. Anyway, at one point in the movie a character answers a call on one of those really old crank phones where the user lifts the earpiece but the microphone stays on the wall. The caller is asking for someone else, so the character puts her hand over the phone to shout for the intended recipient in the busy building, except the actress put her hand over the earpiece in her hand instead of the microphone on the wall. I’m sure she’d never used that type of phone before, but I chalked it up to the inexperience of the production team that no one caught that goof.