Other mistake: Numerous students with large amounts of blood splattered on them from three students in the classroom "exploding" and others "popping" while going down the steps were able to go through the door - some rubbing their shirts against the doorframe and others touching the doorframe with their hands - without smearing blood on the door or frame. (01:01:51)
Continuity mistake: Mara's hair is inconsistent during the prom - the length and tightness of curls varies a few times. Most noticeably, the sides of her hair sometimes only reach her shoulders but other times look three or four inches longer (and this is not merely due to loosening of her curls). (01:14:20 - 01:16:06)
Other mistake: The way Katelyn exploded was described by Mara as being like a balloon popping. Every time a student exploded, blobs of blood (and tiny pieces of the body) splattered everywhere, making a huge bloody mess. When more than one student exploded going down the stairs, blood looked like it was being poured from a bucket. Sometimes, parts of clothing could be saturated in blood (such as a sleeve), but there was always more blood splattered nearby. When Katelyn was at the doctor's office (to get a piece of someone's bone removed from her forehead), "blood" goes smoothly/evenly around her eye to the lashes with no gaps or splatter marks. Blood from an explosion would not fall this "perfectly" around eyes. For example, folds in the eyelids would block some blood from landing in certain places and eyelashes should have some blood on them but Mara's did not. (01:41:27)
Continuity mistake: Mara is wearing a white long sleeve jersey when in the Dalton twins' car accident and when Dylan finds her in the water washing off blood. Dylan offers her the gray sweat suit he has in his backpack, but Mara says she isn't wearing it (because they wore those clothes at the police station). When Mara stands up, she has on a dark green T-shirt with a lighter green large circular design on the front. Mara is wearing the green top when she gets to quarantine, as well as later in the movie. This is obviously Mara's top, so where did it come from after she refused to wear the gray sweat suit from Dylan's backpack? (00:33:42 - 00:35:02)
Suggested correction: After rewatching the movie, I noticed that Dylan was POSSIBLY wearing this T-shirt under his jean jacket on his first day of school; the shirts look similar, but little can be seen because it is under the jean jacket. At the same time, Dylan's backpack at the accident scene did not look full enough to contain both parts of the sweatsuit, so it is a stretch to believe the T-shirt was also inside. Moreover, Dylan told Mara that he had a crush on her for two years, so the "old" T-shirt would have just happened to be in this backpack under the sweatsuit worn at the police station. Dylan is thinner than Mara, so it is unlikely that his T-shirt would fit her. When I rewatched the movie, I noticed that the T-shirt in question looked navy blue when Dylan had it on but green when Mara was wearing it.
Revealing mistake: In the opening pre-calculus class, Mara bending over to the side of her desk is what enabled her to avoid being splattered when Kaitlyn - sitting in front of her - "exploded." It was also a cue that the "blobs of blood" were about to be strewn across the classroom. The boy seated at the last desk behind Mara moved his right hand up to his forehead (similar to how one would block sunlight) in anticipation of getting splashed with blood. After some of the "blood" landed on him, he quickly moved his hand away from his face. (00:00:35)
