Factual error: It is roughly 120-135 dB inside of a C-130, especially one that hasn't been specifically modified. It is so loud that it is painful to be in the cargo hold without hearing protection (besides it being outside of military regulations) and you certainly couldn't have a normal conversation while it was in flight.
Factual error: When Cruise and Wallis are in the underground tunnel beneath London they are walking along the tracks before a Tube train blasts through. The 3rd rail is missing, which carries the electricity for London Underground trains and would have electrocuted them both if it was there as it should be.
Continuity mistake: When Ahmanet enters the Crusader burial chamber, she walks in holding the dagger with her right hand and then picks up the stone. As the camera takes the close up shot, it is very clear that she picks up the stone using her right hand. When the shot changes, she is now seen holding the stone with her left hand. (01:22:55)kangoedin
Revealing mistake: During the underwater scenes the light appears from below and above but it's underground and should be pitch black, suggesting studio lighting being used.
Factual error: As the plane is crashing, it is shown in a nose dive, but the actors are shown rolling around in it like a barrel. Everyone should have been piled up against the cockpit bulkhead.
Revealing mistake: When the coffin is dragged onto the plane, you can see wheels that are set in the underneath of the coffin. It's supposed to be a flat bottom and a continuous scene from helicopter to plane, so no time to use a trolley.
Plot hole: When the C-130 transport is falling from the sky, the Egyptian sarcophagus remains lashed to the plane's cargo deck. The crew exploring the wreckage says they are miles from the 'primary crash site' (so that nasty stuff can happen to them without witnesses). The sarcophagus would still be at the primary crash site, along with the remains of the fuselage and cargo deck. (00:32:50 - 00:36:00)rgbfoundry
Factual error: Jenny dates the sarcophagus as 5000 years old and explains later that the hieroglyphs are from the New Kingdom which dates from 1550 to 1070 BC - just around 3000 to 3500 years before.