10 Worst Movie Mistakes Of 2021 (So Far)

The Tomorrow War takes place in the future when aliens have wiped out most of humanity. This apocalypse compels scientists to send time-travellers in the past to recruit people to fight in the future. Our hero, Dan Forester, is recruited for this battle and is given a technologically advanced armband that allows him to travel through time.

Because this band is crucial to the plot, you'd think the filmmakers would take special care to remember which arm its on. Even though the device is meant to be on Dan's left arm, it occasionally switches over to his right.

This blooper is most obvious when Dan falls into a swimming pool after he time-jumps for the first time. Though the band is on his left arm when he hits the water, it swaps to his right while he dives under and switches back to his left arm when he surfaces. Mistakes like this can happen if the shot is flipped, but since there was no reason to do that for this scene, it's a mystery how the filmmakers didn't notice this error.