Dennis Quaid -- Funny Or Die Owns It ... We Made Him Freak Out

Dennis Quaid really did freak out on a movie set -- but it was the staged set of a Funny or Die video.
The site finally copped to shooting the scene with Dennis ... by posting the full video showing Dennis losing it on the director and the crew of a fictional set. But now you can see the full skit which includes some hysterical sight gags.
The video leaked earlier this week ... just showing Dennis losing his marbles.