Character mistake: When Wood is telling Harry the rules of Quidditch he says that if you catch the Snitch the game is over, which is true. But then he also says that which ever seeker catches the snitch, their team wins, but that isn't true. Granted that the 150 extra points probably would give you the winning lead, but as JKR pointed out in the 4th book at the Quidditch World Cup, you can catch the Snitch but lose the match. And you'd think explaining the rules to a first-timer you would want to get it right. (01:05:40)
Suggested correction: The team whose "seeker" catches the "snitch" would win in over 90% of matches. At this point, in the film and the book, while Harry Potter has discovered that Quidditch is popular in the wizarding world, he knows nothing about the rules or how to play. Oliver Wood is giving Harry Potter his very first introduction to Quidditch. So maybe it is acceptable for Oliver Wood to give a general overview of how Quidditch works, rather than outline every nuance and detail of every game ever played.
Character mistake: When Jimmy explains to the kids of the town where the aliens took their parents, he mentions the origin of the aliens being somewhere in the Orion Star System, 3 million light years away. The Orion system is way closer than that. It is actually less than 1400 light years away from Earth. 3 million light years away would place them further than the Andromeda Galaxy.
Suggested correction: This shouldn't be a character mistake. A genius like Jimmy would know something like this. It's basic astronomy.
That's exactly why it's a character mistake. A character mistake is when a character does or says something that they shouldn't based on who/what they are suppose to be, or something a character wrongly states as fact when they should know better.
Character mistake: At the FBI facility, Agent 11's handler buckles the collar on the dog's neck. Later, when Gordon has put the collar on and tries to get it off, he's trying to pry it off. He just buckled it on not two minutes earlier. He's stupid, but not that stupid.
Character mistake: When Mike pulls out the first Scare Report, the word "yield" is spelled wrong.
Character mistake: When they find a Suicine, they ask Oak and he says it's a Swecon.
Suggested correction: I watched the film, and Professor Oak pronounces Suicune's name correctly.