I know this is a longshot,
In the 1977 James Brolin movie The Car (about a demon-possessed car) there’s a scene where some American Indians who witnessed a hit and run killer give their statement to an American Indian cop. The cop then translates their story for Brolin. Soon after a woman tells Brolin the cop deliberately ommitted the part about the Car having no driver, presumably because he thought Brolin would dismiss their story.
It’s an important scene because it’s the first time the oddly-named Sheriff Parent (Brolin) realizes the Car has no driver.
I’ve only seen The Car once about, but as soon as this scene began I knew how it was going to unfold, and I’ve definitely seen the entire scene in another movie… a non-English speaking witness deliberately has their stody mistranslated, then someone else overhears and tells the sheriff the truth. (Does anything like this occur in Close Encounters?)