Character mistake: The actor who played FBI agent Ross is Lennie James, who is an English actor. When they are searching for the girl in the parking garage of her building, he orders the SWAT team and other agents to search everywhere, under the cars and to "check the boots." He says this twice. Boot is the British term for trunk. He should be telling them to check the trunks of the cars, not the boots.
Character mistake: During the interview with Dr. Sanjay Gupta, Alan Krumwiede incorrectly describes what an R naught of 2 means. He claims on Day 1 there were 2 people infected, then 4, then 16, then 256... This is raising each number to the 2nd power (squaring each number.) But we learned earlier in the movie from Dr. Erin Mears that the R naught indicates the number of people who will become infected by 1 infected person. So to calculate the spread of the disease, each # of infected should be multiplied by 2, not squared. It should go Day 1 = 2, Day 2 = 4, Day 3 = 8, Day 4 = 16, Day 5 = 32, etc. (01:06:35)
Character mistake: Alan Alda says that his personal security code is the street address that he lived on at Steinway Boulevard when he was a kid growing up in Astoria, NY. The name of the street in Astoria is Steinway Street. (00:19:50)
Character mistake: When the American hands over the wills to Ian Fleming he calls him Lieutenant Commander, but when Fleming turns up at the camp he has gold braid on his cap - only commanders and above wear gold braid. Also they kept calling the RAF guy Flight Sargent but he didn't have a crown above his stripes.
Character mistake: 2 men are watching the cameras with Bishop rolling away from the exploding truck. One man says to watch camera 2, but they are actually showing 1 in the upper left corner.
Character mistake: Dr. Erskine says he lives in Queens at 73rd Street and Utopia Parkway. Actually, 73rd Street is well to the west of Utopia Parkway (both run north-south). Erskine must have meant 73rd Avenue, which does cross Utopia Parkway.
Character mistake: When trying to teach Banshee to fly, he is told to make his sound waves super sonic. Sound waves cannot be super sonic. Sound can only travel at the speed of sound, it always does. I guess they were trying to tell him to use a very high frequency, but the speed would still be the speed of sound.
Character mistake: When the posse is heading out in the morning, one guy says that it's heading north and they start riding in the direction he's pointing. However it's supposed to be first thing in the morning, and you can see the shadows of the horses cast to the left of screen while they are riding towards the camera. The sun rises in the east, which would be right of screen with the shadows cast towards the west. Since they are riding towards camera, this puts them heading south.
Character mistake: Near the end of the movie, Dr. Bennett told Nathan that he could live with her and be able to finish the school year (without having to transfer). Assuming Nathan was a minor (under 18 years of age), Dr. Bennett did not have the legal authority to simply take custody of Nathan. There are proper court procedures to follow; a judge would have to agree and sign a court order declaring Dr. Bennett as Nathan's (temporary or permanent) legal guardian.