Deliberate mistake: Leaven spends too much time thinking about if 645 and 372 are prime numbers to be believable. But she knows the factors of 649 and the result of 26 to the power of 3 almost immediately. Plus anyone with any maths knowledge whatsoever would know that any even number (or one divisible by 5) can't be prime, so 645 and 372 could be dismissed without even thinking about it.
Continuity mistake: Much of this movie was shot in Luxembourg, not in Paris. This is obvious on several occasions - the road signs are clearly not like the French standard. You even see a sign to »Trier (Trèves)«. In Paris, there would be no signs to this German town...and even if there was, these would say »Trèves«. The buses also have French registration plates but are from Luxembourg companies.
Continuity mistake: When Wynn is talking to Al about the mission to blow up the plant, Wynn puts his cigarette out in the ash tray in the scorpion bowl and there are 4 butts in the ash tray, but a minute later when the camera shows the 2 scorpions fighting, the ash tray has no cigarette butts in it. (00:11:19)AzN InVasian
Plot hole: In the scene where Lewis and Clark nearly hit the Event Horizon, One of the crew is calling out the closing distance and another confirms this information. Regardless of clouds obscuring their view they were aware of their proximity and the fact that they were speeding towards it and forced to attempt an abrupt stop makes no sense.
Continuity mistake: After the explosion in the laboratory, Josh is laying on the floor, injured. His face is covered in blood, however during the scene the amount of blood on his face keeps changing. In close ups of his face his lips are free of blood, but in wider shots his lips are covered in thick amounts of blood.
Continuity mistake: In the end when the Kothoga is on fire and chasing Margo, it catches up to her in moments. However, everytime it dramatically changes angles, the Kothoga appears a lot futher away than it was previously, but soon after catching up once again. Noting her progress in the room, this situation is not simply replaying the same scene from different angles. Plus when she gets to the water tank, she has plenty of time to spare to hit a lever, climb the device, and jump in before the Kothoga looms overhead.