Other mistake: Rick's son screams for him during the rescue from the pygmies and Imhotep, but how did Alex know his dad was running in to save him, if he thought they were killed by Imhotep during the river consuming the ship in midair?
Suggested correction: Maybe he was hoping his dad was still alive and called out in the hopes that he still was. After all, nobody saw the bodies and just assumed that they all died.
Other mistake: When they are flying the dirigible through the night you can cleary see that there is a repeated pattern in the stars.