Continuity mistake: When Jay and Silent Bob first get into the van with the girls and Brent, Brent reaches out to squeeze Justice's thigh with his left hand, but as the camera picks up the actual squeeze, it's Brent's right hand squeezing her thigh. (00:24:30)
Continuity mistake: Right after Jay and Silent Bob run off the Good Will Hunting 2 set from the security guards, they run outside and Jay's jacket is tied around his waist. Then, they run into the Scream movie set and he has his jacket on. As soon as they run out of the Scream movie set, his jacket is tied around his waist again.
Continuity mistake: Near the end when Jay and Silent Bob fight Mark Hammil, Jay takes out the double sided bong saber and takes a hit from it; you can see the plastic lightsaber part of the other blade in the corner of the screen. It's white and green.
Continuity mistake: During the scene where Brodie talks to Jay and Silent Bob about Bluntman and Cronic, he shows them a copy of Wizard magazine with a related article. On the right page is a picture of Holden and Banky. They then take this magazine and eventually show Holden McNeil the same article. The right hand pictures are different from how they were before.
Continuity mistake: During the shootout at the end, J and SB are hiding behind the car and a shot pierces the car between their heads. In later wide shots, the bullet hole is missing.
Continuity mistake: In the scene where George Carlin is telling Jay and Silent Bob about hitchhiking, the pole thing behind them appears and dissappears from shot to shot.
Continuity mistake: During the last scene with Morris Day and the Time performing on stage, after Jay kisses Justice she makes "Kissy" faces at him. When the camera cuts, she is no longer doing so.
Continuity mistake: In the scene when Wildlife Marshall Willenholly joins the Utah Police in front of the Diner, the police cars move closer together and farther apart to allow for the marshall to walk from behind to in front of the cars.
Continuity mistake: In the scene where Jay and Silent Bob are getting busted, the cop is holding the pack of "wraps" in the air. When the shot changes so that Jay can pull down his pants, the cop's hand is down.
Continuity mistake: When Holden is reading the posts on moviepoopshoot.com, the right side of the browser window changes positions. It will change where the window takes up the whole screen, to where the window is smaller and you can see several icons to the right of the window.
Continuity mistake: Towards the end of the film when Jay and Silent Bob battle Mark Hamill, Jay cuts off Hamil's huge hand, and you see it drop to the ground, and you see his smoldering arm with no big hand. In the next shot when Mark Hamill is fed up and marches off camera, you see he once again has his huge hand attached to his body.
Continuity mistake: Near the end when Justice is talking to Federal Wildlife Marshal Willenholly after he's been shot by the orangutang, Justice's hand moves between shot. It goes from knee to floor and changes several times.
Continuity mistake: Near the beginning of the movie when Jay and Silent Bob are in the comic book store talking to Brodie, watch the man who is leaning against the wall reading the comic book. (the one Jay teases while walking past) In one shot he has the comic, then a second later he doesn't, and finally a second later he has it again and walks away. [For anyone who has seen or owns the 2 disc dvd of the film, and has watched the second disc, it will have tons of deleted scenes, including one for this scene. It shows Brodie having a go at the man for bending the spine of the comic book, and smacking the comic out of his hand. He then walks off, the guys feelings is hurt and leans against the wall, and the film continues.]
Continuity mistake: Near the very end of the film, Jay and Silent Bob are going around beating up everyone who posted bad comments about them on the internet. When they beat up the guy in the convenience store, a bunch of items fall off of the shelf behind him. When the camera keeps cutting angles, you can see that the items are back on the shelf and in different order.
Continuity mistake: When Justice is talking to the other girls (mainly Sissy) up at the balcony of the motel room, there are some clouds in the sky. However, between shots suddenly the sky is completely clear. (00:48:41)
Continuity mistake: In the comic store, "Brodie's Secret Stash," if you press "pause" right when Brodie reaches for the Bluntman and Chronic comic book to show Jay and Silent Bob, you will see that he is right across a comic entitled "Cable." To the right of that is another comic, "Captain America," and if you can recognize it, to the right of the "Captain America" comic is a "Captain Marvel" comic. If you look behind Jay, you can see the same exact thing.
Continuity mistake: Near the end, when Jay and Bob are revenging against all those who dissed them on the internet, they read from a stack of computer printouts of the insults. In one shot, you can clearly tell that when Jay repeats a paragraph of an insult to a kid, he reads from what looks like a few words on the paper. In fact, the entire paper looks like a list of the same label repeated.
Continuity mistake: At the beginning of the movie, when Jay and Silent Bob are singing about blunts and stuff, a man comes out of the store and is about to walk by Jay and Silent Bob. When it closes up on Jay and Silent Bob, the man never walks by.
Continuity mistake: In the scene where Jay and Silent Bob go to speak to Holden McNeil (Ben Affleck), Ben shows them the internet site, moviepoopshoot.com. Well in the address bar it is clearly not http://, but file://, which means the site was being shown locally on the hard drive, not with a connection.
Continuity mistake: During the gunfight at the end Will Ferrel's and the vixen's model of firearms change a few times.
Answer: Apparently it was a song that was improvised by Jason Lee and Jason Mewes. Stated on the commentary.