Factual error: During the Mars-flight, the way the spacecraft uses the rocket thrusters is unrealistic. For example when they are nearing Mars, they should be using the rockets against their movement, to slow down the speed. But in the movie they are using the rockets towards Mars.
Factual error: Crew members aboard the spaceship at the planet Mars are shown in instant communication with Earth. Because of the distance, a few minutes must pass each time before communication is made (between 10 and 22 minutes depending on where the planets are in their orbits, and that's each way so at least 20 minutes from when you say something until you hear what they say back).
Plot hole: The rape scene in the parking lot... there is no one around for THAT long? But wait, once the detectives come in the scene two people are walking in the background with a shopping cart - they must have seen something!
Plot hole: One scene we are in the alien's (when she is still normal) living space and we can hear through a speaker everything the scientist is saying...wouldn't the alien pick up that something was happening and do something before...?
Continuity mistake: In the scene where Eve is contemplating mating with Dennis Gamble in her lab, you can see her in the door's reflection standing. After rejecting him, she sits is a chair and turns away. The following shot shows Dennis's reaction to be rejected, but also show Eve's reflection still standing.
Continuity mistake: In the scene where Eve breaks out of her glass room lab, she is wearing a long green summer dress that is open almost from the ground to her waist revealing white underwear when she jumps down from the lab. In a later scene with Patric Ross at the barn she unbuttons her dress, steps out of it and is naked, sans underwear.
Continuity mistake: When the Debutante begins to examine herself in the mirror the jewel on her necklace is missing, it appears again when she reacts to her stomach expanding.