Deliberate mistake: It is totally unlikely that a museum as careful and important as the Smithsonian would leave the crates un-nailed, which could make the pieces inside get damaged. Of course if the crates weren't open, none of the figures could come up to life.
Night at the Museum: Battle of the Smithsonian (2009)
1 deliberate mistake - chronological order
Directed by: Shawn Levy
Starring: Robin Williams, Owen Wilson, Ben Stiller, Amy Adams, Steve Coogan, Hank Azaria
Visible crew/equipment: In the scene with Darth Vader and Oscar the Grouch, watch Darth Vader's eyes. You can see the light screens and crew reflected in his eyes in every shot.
Larry Daley: I'm sorry. Last time I checked, I thought we lived in a free country. So...
Smithsonian Security Guard: No, we don't.
Larry Daley: No?
Smithsonian Security Guard: It's the United States of "Don't Touch That Thing Right in Front of You."
Trivia: Five different actors from the U.S. and U.K. versions of The Office appear in the film: Amy Adams, Ed Helms, Mindy Kaling, Craig Robinson, and Ricky Gervais.
Question: Couldn't Jed, the cowboy in the timeglass, just be walking around on top of the sand to avoid being buried in it?
Answer: Yes. But he obviously doesn't think to do so.
MasterOfAll