The mistakes of the Setters of Catan game are really bad. But who cares?
It depends on the standards of the people putting on the show. It depends on how much research you're willing to put in for the sake of verisimilitude.
I did a show of Escanaba in da Moonlight (if you haven't heard of it, I wouldn't be surprised). The plot heads toward a game of euchre. The four of us sit around a table and play a couple of hands. Every night before the show, I would stack the deck. Part of the plot is that my hand magically turns into a hand with 2s, 3s, and 4s (which is impossible in euchre). I also stacked it so that people who took tricks actually won the tricks (if you don't know euchre, imagine watching a game of Spades where someone plays the ace of spades and loses the trick). And that wasn't that easy, because even dealing a hand of euchre is a strange ritual where you deal 2 cards to every other person and 3 cards to the remainder, only to reverse the numbers.
My point? Actually, not much of one. It possible that nobody noticed. I was facing the audience, so people likely wouldn't see my cards anyway (except for when I threw the cards on the table). Still, I put forth the effort. The director put forth the effort to make sure we did it correctly. Maybe one person noticed, and he would have been impressed by how real it was.
Is it terrible if a show shows a game incorrectly? No. But it is far more impressive when it's clear they've done their homework.