It's a Mad Mad Mad Mad World (1963) - 8 major mistakes

Continuity: In the last scene when they are all on the fire escape, there is one part where the landing nearly collapses and Sylvester is seen nearly flying off the landing.  The next immediate shot shows Sylvester fighting for the ladder.  He apparently climbed up the landing and crawled over a bunch of people in a fraction of a second.

Continuity: In the scene where Dick Shawn and all the characters find the box of money under the big W, Shawn has just thrown Jonathan Winters out of the hole so he would have room to work. But in the next five edits, Winters is both in the hole helping Shawn struggle with the box and is also shown standing outside the hole observing himself along with the others.

Other: When the English guy and Russell are in the car watch the background - all of a sudden it changes.

Continuity: About three quarters into the movie, Sylvester, in his red '62 Dodge Dart convertible, sees brother-in-law Russell Finch and Mr. Hawthorne drive by in a '61 blue Chevy Impala. When Sylvester does a u-turn to give chase, you can see the passenger side of the Dart is already caved-in. A few moments later, when he rams the Dodge into the Chevy, kind of Ben-Hur chariot style, is when the initial damage should have occurred. Evidently, the chase scene was filmed out of order. Also, prior to the chase, the Dodge is shown primarily from the driver's side, perhaps to conceal the damage on the passenger side of the car.

Continuity: When the couple in the truck are driven off and down the side of the mountain the direction of the truck does not match the direction he steers the truck.

Continuity: The money in the suitcase is neatly bundled when the Captain takes it. When the suitcase bursts open on the fire escape, individual bills float out over the crowd.

Revealing: At the end, the bodies falling off of the fire engine ladder are obviously dummies.

Continuity: When the fire engine escape ladder begins swaying out of control, the actors and stuntmen are never in the same place on the ladder from scene to scene.