Deliberate mistake: Being merely a comedy bit it does not have to make sense, but Dave Bautista's mom solves the puzzles without even being able to look at them from her sitting spot. You could argue she somehow could figure out the nature of the compass from the first glance she took solving the stereogram, but the Fibonacci sequence was not on display yet. Also, Duke joins the call saying that she "did something" to the box, it "opened up" and she "broke it", but actually he never saw any of that that, the puzzle was already open in the background before she'd even tell him there was a delivery.
Deliberate mistake: One of the first shots in Greece shows Benoit Blanc and Lionel standing on the pier. As director Rian Johnson himself says in an interview for the Vanity Fair Youtube channel, "Matches nothing else in the scene lighting-wise, but it's gorgeous soooo...who cares." (00:13:30)
