Factual error: If you've ever been to Sydney you'll realise howw wrong a lot of the locations are in this film. For example the girls are apparently "surfing" at Manly Beach, a huge surf beach almost three kilometres long on the Northside of Sydney. The girls actually "surf" at a waveless, inner-harbour bay about one hundred metres long that I believe is in the Eastern suburbs. You can actually see land beyond the water.
Factual error: When the dad comes out you see a dog. The dog looks fake because dogs don't bark while snarling.
Continuity mistake: When Mary-Kate and Ashley are near the museum, the camera shows the museum from the outside. You see one of the thieves start to run out. Then it goes inside the museum and the guys are stealing the jewel. Then it shows the museum from the outside again and it shows the guy running out just like he had before.
Continuity mistake: When they have a "break" and have a party, they throw confetti up in the air. When they come back to reality and hear that they are to be moved to another location, one of them still has confetti on their shoulder even though it only existed in their "fantasy".