When there is a fight at the Blue Oyster Bar and Hooks go to find the address, Proctor says the address is 621 Cowan Avenue. When Mahoney and Hightower get there, the number on the door says 655.
Officer Jones' hat falls off his head twice when he jumps over the fence.
When Jones jumps up on the loading dock in the karate fight scene, he is wearing his gunbelt. In subsequent shots, he is not wearing the gunbelt. It is not shown on the dock where it would have been if he had removed it prior to the fight.
In this film, the Blue Oyster is located on Cowan Avenue. In the first movie, Mahoney mentions "it's on Howell".
Around the middle of the movie when Officer Jones is fighting in the "Bruce Lee" scene, the clerk unloading the produce from the truck is seen sitting in an upright position when the camera is focused on him, but is seen in a slouching position when he is in the background of the fight scene.
(at around 57 mins) In the Japanese restaurant scene, the teppanyaki chef greets Pete Lassard (Howard Hesseman) by saying "ohayo gosaimasu, ohayo. Good evening." "Ohayo gosaimasu" is Japanese for "good morning." "Ohayo" is a less formal way to say the same thing.
Epoxy glue requires two ingredients, a resin and a curing agent. Tackleberry had both on the table when he was gluing his helmet. However, Mahoney only put one of the bottles in the shower with Mauser which would have done nothing.
After Tackleberry tells Mahoney that he is in love with Kathleen Kirkland, he asks him to "keep this 10-35", obviously meaning to keep it a secret. 10-35 is the radio code for backup, while 10-36 is the code for confidential information.
When Jones imitates Bruce Lee, the movement of his lips does not match his words. It is done deliberately, as a joke on the poor English dubbing of Lee's films.
Although a window breaking sound effect is heard when Sweetchuck jumps through the store window, there is no glass seen in the pane.
When the two young boys are running from the alley gang, the larger boy, Paul McMichael breaks character by slowing down to walking pace just before he is out of frame.
When Sweetchuck approaches the automatic teller machine during the opening credits, seen on the wall are shadows of the gang members awaiting their cue to enter the camera frame.
When Mauser is thrown outside nude in public, you can briefly see his white underwear. However, this is applicable only to the open-matte full-screen transfer for the home video release. When presented in its original aspect ratio, this detracting detail is not visible.
When Mauser is accidentally pushed down the hole, atop the old zoo, the rock formations in the foreground are clearly made of fiberglass, as evidenced when he falls in and it shakes. Additionally, as they're supposed to be on top of the cave, the setting of the roof clearly shows it was built right out in front of the old zoo.
When Tackleberry and Kirkland get back to her place for a little fun, they are busy taking off each others clothes and removing each others guns. The camera pans to the floor a couple of times showing the growing pile of guns and clothing. Kirkland's pink pumps are are part of that pile yet when the camera pans back to the bed, Kirkland is still wearing her pink pumps.
During the scene at Sweetchuck's store after the shootout, when Sweetchuck is trying to escape before being tackled by Hightower, the guy who tackles Sweetchuck is so obviously not Bubba Smith. Much shorter and lighter set, and considering Bubba Smith was an ex-NFL player.
After Captain Lassard gets everyone excited after his speech, a cop says "Let's kick ass!" but his mouth doesn't move.
When Pete Lassard confronts one of the gang members in the alley, the gang member's voice is heard mocking Lassard, but the gang member's mouth does not move.
When Hightower throws the football, the wire pulling the man back is visible and at the end of the shot the man is obviously hanging from it.
Right after Mahoney starts infiltrating the gang, and he's encountering Jones and the other cop, he tells Jones to kick the elder gentleman, then pulls him off all of a sudden. If you listen very closely, you actually hear him say "Jones", but obviously in the excitement, neither of the gang members notice and put 2+2 together.