I see, then you mean the following:
A goof in film making is an error made during film production which finds its way into the final released picture. Depending upon the film and the actual scene, the goof may have different effects: a loss in realism, an annoyance, or it could just be funny. It is often a type of continuity error. Goofs are also known as "bloopers" or "mistake".
There are several types of goofs, for example:
* Somebody or something from the film crew is in the picture that wasn't planned (e.g., camera and cameraman is reflected in a mirror, or the microphone is visible).
* Chronological or conditional errors (e.g. a cigarette getting longer with the next scene, a bruise wandering from the left to right leg, damage to a building that disappears, or moved props).
* Historical inaccuracies and anachronisms (e.g., an HDTV set in a film set in the 1970s, radio tower in cowboy movie).
* Geographic: an object or landmark reveals the scene was filmed in a different city than the city it is set. This is very common in Hollywood films that are shot in Canada.
Goofs can be found in a large number of films, even in very expensive productions. Star Wars IV for example has been counted to have 200 goofs in it, ranging from disappearing props, to a storm trooper hitting his head on an opening door.
In broader usage, a goof is a mistake, or a foolish person. In the context of foolishness, the word was a favorite of Dennis Farina on the TV series Crime Story.
"Goof" has also come to be a slang name for a child molester, especially in prisons. This usage likely stems from the previous usage, i.e., the offender was foolish for making such a mistake.