During the emotional diner scene in To All The Boys I've Loved Before, Lara Jean's cardigan flips from being worn inside-out to being worn correctly.
In the middle of the Clovers' badass final performance in Bring It On, two of the cheerleaders run into each other, a mistake they'd DEFINITELY be marked off for at this competitive level.
When Max gets his note handed back to him in Hocus Pocus, it's clearly not the same handwriting.
The shop-owner whacks a small child in the face with the counter during "The Candy Man" song in the original Willy Wonka and the Chocolate Factory.
And in the 2005 remake, Charlie and the Chocolate Factory, the opening credits show Willy Wonka placing each Golden Ticket by hand of the BACK on the bars, but when Charlie opens his bar later, the Golden Ticket is on the FRONT.
The rider of Rohan to the right of Éomer has a hilariously fake rubber spear during the Minas Tirith sequence in The Lord of the Rings: The Return of the King.
When Thanos' snap occurs in Avengers: Infinity War it's daytime in Wakanda — a fictional country located in Africa — but during the post-credits scene it's ALSO shown to be daytime in New York...even though these two places are in completely different time zones.
The circle cut-out where the punch is about to be thrown is completely visible in The Matrix.
When Wolverine shields Yashida from the explosion in Wolverine, he's badly burned to the point that his hair has literally disintegrated...but his pants are completely fine?
In North by Northwest, you can see a child covering his ears right before a loud gunshot fires, spoiling the twist of the scene.
During the dance sequence in Silver Linings Playbook, Pat already has tape on his sneakers, but seconds later you see Tiffany putting tape on his untaped sneakers.
In The Wizard of Oz, the Tin Man slyly unties the Wizard's hot air balloon while simultaneously looking ~shocked~ that's he's flying away without Dorothy.
A man in jeans and a t-shirt walks by in the background of Raiders of the Lost Ark and, considering the movie takes place in 1936, this is odd.
During the "We Go Together" sequence in Grease, when Sandy hops into the shot she's no longer wearing the shoes she was wearing the entire sequence.
During the throne room fight scene in The Last Jedi, the weapon in the Praetorian guard's left hand vanishes into thin air.
And finally, in Moulin Rouge, Satine's glove switches arms during the "Diamonds Are a Girl's Best Friend" number.