Factual error: Characters who have lost an enormous amount of blood who are not only still alive near the end, but sometimes they don't even display signs of shock from blood loss. In reality, these characters would have died very fast.
Common movie and TV mistakes - page 11
This is a list of mistakes, things done wrong, etc. that happen so frequently onscreen we barely notice any more. 'Movie logic', stupid behaviours, and everything related.
Deliberate mistake: In many instances, when a traumatic incident in a story has been resolved and taken care of, the story will gloss over the recent events and the characters will celebrate as if it's a happy day to be alive, rather than still adjusting to the almost tragic events that have taken place very shortly before. But of course, there wouldn't be as much satisfaction or catharsis for the audience if that were to happen.
Factual error: Mostly in horror films, people going through prolonged periods of physical pain or torture never fall unconscious. In reality, they would pass out much quicker under so much pain.
Deliberate mistake: When someone gets into a car and drives away the doors are unlocked with the keys already in the ignition.
Factual error: In recent years, blood tends to be represented with a certain degree of realism, but in past eras especially before the 80s, the industry standard for fake blood appeared to be a much brighter red that often looks odd to a contemporary eye, and distinctly fake. In general, every movie sorta has its own 'blood' not necessarily factually accurate.
Factual error: In numerous sci-fi films and TV series, planets, moons, and other similar celestial objects always appear to have gravity equal to that of Earth regardless of the object's size or mass. For example, a moon the same size as a small planet (such as Yavin 4 or Endor's forest moon from the Star Wars films) has the same apparent gravity as larger bodies, while in reality, the smaller objects would have noticeably less gravity than larger ones.
Factual error: Police detectives working cases in which they are personally involved; such as the murder of a friend, family member, or their partner. Even though their superiors will often warn them to stay away from the investigation, the cops will continue to work the case on their own. Oftentimes films will imply that the cop should leave the investigation alone "for his own good", but in reality a cop investigating a case they are part of would seriously taint any evidence they uncover. If taken to trial, a defense attorney could easily have that evidence thrown out. Writers tend to get around this by having the villain engage in more crimes and be caught "red handed" or by simply having the villain be killed by the end. However it is still borderline insanity to see a cop investigating his wife's murder.
Other mistake: A character will be slapped in the face, but their face won't be red afterwards.
Factual error: Hotwiring any car made more recently than about 1995.
Audio problem: No matter the size of the gun, or where the gun is fired, it always sounds like a huge shotgun going off in a echo-heavy canyon.