Revealing mistake: When the Rangers kick Oozemen's ass, the pink Ranger starts off with the "You guys make me sick sick sick -kick". While all Rangers are fighting, the blue one is just standing still next to the camera. You can see his shoe in the in the lower right corner waiting for his entrance.
Factual error: Various Sydney landmarks can be seen throughout the movie (although the Centrepoint Tower and the Monorail play major roles). There are also some cars that have right-hand steering wheels despite the story being set in California, and some Australian model traffic lights (foot-long black cover with a grey pole) can be seen when the Scorpion bot destroys a car in front of the rangers.