Making movies is a taxing business, where hundreds of eyes are looking through filmed footage, making sure that everything went as expected. Even then, mistakes are bound to happen, since all of those people are just human. If you look at something for too long, believe it or not, you’ll end up seeing less and less details.
These mistakes don’t detract from the craft, and in some cases, they are impossible to catch without knowing. But once you do, they become something endearing to look at, like a peek behind the veil. They make us enjoy movies far more, reminding us of the human factor behind the lens.

Gladiator
During a battle scene, a chariot flips over and briefly reveals a visible gas canister underneath. The modern prop accidentally left in frame became one of the most widely shared movie mistakes.

Braveheart
In one of the battle scenes, a crew member wearing modern clothing and a baseball cap is visible among the fighters. The anachronism stands out once noticed.