Revealing mistake: When the leading hitman jumps from the balcony you see him land on a rubber mat.
Continuity mistake: When the Senator is about to be sacrificed, the cloth on her mouth immediately disappears for a split second. (01:29:35)
Continuity mistake: It was briefly stated in the second film that the T-Virus was created by Dr. Ashford to cure his daughter Angela and that the Red and White Queens were based on her. This movie contradicts that by suggesting that Dr. Marcus created the T-Virus to cure his daughter Alicia, and that the Red/White Queens were modeled after her. While the rest of the movie stays true to the continuity of the previous films, this rather obvious ret-con is still a major continuity gaff.
Factual error: In the first scene where Dr Strange is preparing for surgery he uses improper surgical gowning technique breaking aseptic protocols. Strange puts on a mask after washing his hands, contaminating his clean hands by bringing them in proximity to the non-sterile environment of his face. Surgical masks must be worn before the full washing of hands. Another error is that he inserted his hands all the way through his gown to don gloves. Hands must never leave the sleeves and gloves must be put on with the sleeves still covering.
Plot hole: When the group is walking through the jungle for the 2nd time, they have nothing more than their backpacks and a horse to accompany them. Suddenly we see them rowing down a river on a boat and raft. After making peace with the savages, when they have to let a group member go to get medical help, they have been washed ashore as they have been traveling on a single raft since the canoe was damaged by spear attack. How is it that they had a horse and an Indian guide to send away with their injured man? (01:16:55)
Continuity mistake: When Mrs. Otterton is in Chief Bogo's office holding her family photo with both paws, in the wideshots her purse is hanging in the crook of her left arm, but after a brief shot of Judy, when it cuts to Mrs. Otterton's closeup as she tells Bogo about her two beautiful children her purse is gone, then after another brief shot of Judy the purse is back in its place again in the wideshot.
Plot hole: Prior to the final show, when the horsemen are performing separately at different locations in London. [Scene X] Jack is busy with his card swap trick. While others are doing their tricks too, [Scene Y] McKinney is believed to be tricked once again by his face sharing brother at another location... Dylan gets a call and then he calls everyone to wrap up and meet somewhere. [Scene Z] Jack also wraps up and leaves the place... OK. Later after the expose in final show McKinney tells the story about how Jack successfully hypnotized his brother [in the Scene Y]. How could Jack be at two different locations at the same time? He was performing somewhere else when he did hypnotism at another location and then wraps up his trick back where he started.
Visible crew/equipment: When Dewey is introduced and has a phone call with Jeffers about the leak, he is packing away files in a briefcase. On his desk there is a pad of paper beneath Dewey's mobile, and the scripted lines for Dewey's side of the phone conversation are handwritten on the top sheet, not being removed from set prior to filming. (00:08:25)
Continuity mistake: The doctor starts out carrying a Holland and Holland "Royal" Double Rifle; but when he and Tarzan pursue the train, the doctor loses his H&H rifle in the leap from a cliff. Lo and behold, after they commandeer the train and disembark, the doctor is inexplicably carrying his H&H Double Rifle again. The H&H is not a common rifle, even today, and his chances of just discovering an exact replacement aboard the train is beyond coincidental.
Continuity mistake: Periodically, we see beyond the wall, where it appears to be heavily forested just beyond the wall and a distance beyond. However, once past the wall, the group starts with a cliff down and then it is completely barren, with completely different weather conditions (frequent red rain).
Plot hole: After an assault on the scale that's been witnessed, covering a wide area of London by extremely well prepared attackers, there's no way Marine 1 would fly to the airport at low altitude within easy range of missiles, and then when attacked, double back over the areas that have already been attacked where hostiles would still be present.
Factual error: Jan Strook is a Dutchman; throughout the movie he is referred to as "Jan Strook", which rhymes with "took," when it should rhyme with "broke." This is even worse considering he has a Dutch accent in the movie, which leaves him no excuse for mispronouncing his own name.
Factual error: When Eakins returns to the house after he swears an oath to the union. You can see a thermostat on the wall behind him. (01:40:00)
Continuity mistake: When Batman goes to save Martha, he pulls the wooden box with his gun and throws it at one bad guy. The guy's head hits the wall, leaving blood. Later on, you still can see the dead guy but there is no blood on the wall any more. The blood appears again when Batman is about to finish off the last person who was stabbed and pinned against the wall. (02:17:30 - 02:18:35)