

Most dishonest about? Hard to say, since movies are dishonest about virtually everything. (As escapism, that’s what we want.) But a big one that comes to mind is proceedings in courts of law.
In real life, a court case is excruciatingly procedural, spread out over months of correspondence and brief hearings, and the vast majority of them never go to trial. And for the few that do go to trial, there are never any intense, witness-stand confrontations, or inspiring speechifying by the plaintiff or defendant. No attorneys shouting, “OBJECTION!”, across the room.
I know of two friends of a friend, one of whom signed a reverse mortgage on his house with some scammers who promised that he could live the rest of his life there, but then who turned around and filed to evict him. Clearly influenced by dramatic courtroom scenes in TV and movies, he seemed to think that “court” meant that he would be able to show up and give the judge a moving soliloquy about being a righteous, disabled veteran, and prevail. The judge did his level best to help the guy out by almost insisting on appointing a guardian ad litem (free attorney!), but he refused. (Sadly, he died before it went to trial, and the scammers kept the house.)
The other one got sued by a credit card company over a charge that was obviously bogus (i.e. from a swimming pool contractor in eastern Europe, which is just who you’d call in the midwestern U.S.), but they had the same mental script: Show up in the courtroom and speechify to the judge. They didn’t even respond to the summons and complaint, and the company won by default judgement.
It’s maddening.

Never heard of it, but it sounds interesting. Thanks!