Other mistake: After Cage calls Gandolfini and tells him he knows about the murdered girl, Gandolfini uses the telephone. There are 13 beeps, then Cage replays it and there are 12. Telephone numbers even with the "1" and area code, only have 11 numbers. (01:01:10)
Other mistake: In the scene where Max is all beaten up, Machine slashes his throat and you can clearly see that the knife's blade is dull, because there's no cut or blood. (01:21:55)
Answer: A snuff film is a movie where someone is actually killed on film, where the intention is to sell the movie afterwards. There are several other instanses where people are shown murdered on film (news reports, the Zapruder film, dictatorships documenting executions, etc.), but if the purpose of making the movie is not commercial, it is not a geniune "snuff" film. FBI experts and other law agencies state that they have never seen a genuine "snuff", and that it is most likely just a rumor, especially since the concept of someone willingly selling evidence of their own crimes to strangers and remaining undetected for 30 years, is highly unlikely. See http://www.straightdope.com/classics/a5_258.html for more details.
Twotall