Continuity mistake: When at the end, the Omni-Droid is walking past Frozone's apartment and he is putting on the aftershave, he turns around looking for his Super Suit and the aftershave bottle turns itself around.
Other mistake: When Bob is getting chewed out by his boss, his boss starts talking about clocks and says "there are also dual cogs." However, the subtitles say "there are also jewel cogs", and the subsequent conversation therefore makes little sense. (I saw this on the collector's edition DVD).
Continuity mistake: Throughout the entire film Violet's fringe keeps swapping sides.
Continuity mistake: At the dinner table when Dash and Violet are fighting and Bob intervenes by lifting the table, the lamp above is not moving. Even after Frozone comes to the door and Bob lowers the table and they all get back into place, the lamp still hasn't moved. The shot switches to Frozone, then back to the table where suddenly the lamp is moving and Helen reaches up real fast to stop it from moving.
Revealing mistake: When The Incredibles and Frozone are about to fire the robot's rocket claw, Helen turns off the rocket with the first button on the remote (round button). When she fires the rocket, she turns it back on with the last button on the remote.
Continuity mistake: When Mr. Incredible opens the window of the RV when the family are flying to the city to save it, you can see lots of paperwork flying about the cabin and exiting the now-open window. However, when the camera does the outside shot of the RV in flight, there's no paper.
Continuity mistake: In the scene where Bob and Helen are arguing after the rescue, when Helen says "Tell me you haven't been listening to police scanners again?", she puts her hand on her head. In the next shot, her arm is down by her side.
Chosen answer: If any object can move across the water quickly enough, the weight isn't transferred completely. In some Scandinavian countries, they actually DRIVE very quickly across water in adapted vehicles. If the character of Dash could actually run that fast, it is feasible and possible for him to run on the water's surface.
GalahadFairlight