In the part of the movie where they are riding on the balloon through the valley, you will notice that Imotep makes a giant wave crash down on them, and you can clearly see the water hitting the pilot. But, in a scene or two later, everyone on the balloon is completely dry.
Which Way Does the Sun Rise?
At the end of the movie, Brendan Fraser and the boy are running to the pyramid before the sun touches it. The sunlight is chasing them from the bottom up, but it is an obvious fact that the sunlight would touch the top of the pyramid first, not the bottom.