Continuity mistake: When LJ speaks his first word, everyone runs into Roz's office where his crib is. They show it right inside of the door. Jack then blows up at Greg when he learns it is a curse word and calls an immediate family conference. Roz, Bernie and Greg leave the room. When they show the family conference, Little Jack and the crib are now gone. (01:10:55 - 01:12:05)
Continuity mistake: During the scene when Gaylord's dad has just found out that Pam is pregnant, Bernie enters the room with a bottle of champagne. he crosses to the bed whilst removing the wire top of the cork in preparation of removing the cork. Cut to Gaylord and then back to Bernie and he is removing the wire again. (01:12:30)
Continuity mistake: During the party at the Good Times Supper Club, when Jack holds out Dina's wine spritzer, in the shots facing Pam the drink has a deep golden color, but in the shots facing Jack the drink is clear. The straw, lime, etc change as well. (01:21:10)
Continuity mistake: When Jack places Jorge's hair in the test tube, he holds Greg's vial, and the name "Greg" is written with the first "G" beside the stopper. However, in the next shot, when he places the vials into the glass, the name is actually written the opposite way, with the last "G" beside the stopper (this is also seen earlier, when Jack inserts Greg's hair). Tape and handwriting differ as well. (01:23:20)
Continuity mistake: Jack drops the two vials into the Tom Collins glass, while in the bathroom. At the hand-off, when he places the drink on the tray, there are no vials in the glass - there is no ice blocking them from view, just a skewer holding a maraschino cherry, a wedge of lemon, and a straw - no vials. Even Jack can't make the two vials invisible. (01:23:40)
Continuity mistake: When Greg sees Jack in the mirror, Jack has one hand behind his back and yet when Greg looks at Jack directly in front of him, both of Jack's hands are behind his back. (01:25:30)
Continuity mistake: When Bernie is lying in front of the bus to protest Jack leaving, in the first shot his head is directly aligned with the wheel well and his feet are under the license plate. When they show Bernie getting up, he is way out to the right of the bus by a couple of feet. (01:32:11 - 01:32:36)
Visible crew/equipment: When Jack and LJ take off in the motorhome, while ignoring everyone's shouts to come back, the crew's blue tent is visible in the reflection on the motorhome's large side, as it turns the corner. (01:35:35)
Continuity mistake: When Jack is leaving the island with LJ, there is a shot with everybody screaming for him to come back and you can see the RV has driven about six feet from Bernie's slippers. Then there's two more shots which takes up about 5-6 seconds with everyone continuing to yell. But afterwards, the RV is only about 2 feet from where it was. (01:35:40)
Factual error: The license plate on the sheriff's car is not correct for a Florida sheriff. Per the state of Florida's DMV (Dept. of Motor Vehicles) website, there should be a yellow star to the left with "sheriff" printed inside. (01:37:35)
Audio problem: At the end when Greg and Pam get married, Kevin plays a song on a set of pipes, however, the notes he plays are wrong - when he blows the short pipes, a low note is made, and vice versa. This should be the other way around. (01:45:45)
Audio problem: As Greg and Pam are about to get married we see Kevin playing the panpipes. The sounds are not in sync with his mouth as he blows down each pipe.
Continuity mistake: When Bernie tackles Jack, the ball drops at his feet, beside Jack. When the camera cuts away, the ball jumps ten feet away from Jack and Bernie moves away from both of them.
Continuity mistake: After the baby escapes from the crib, Greg walks past it looking for him and the gate to the crib is wide open. Next shot, the gate is closed and there was no time for him to close it.
Continuity mistake: All the glasses of wine and the bottle change position and amount of liquid during the dinner scene.
Continuity mistake: After the baby gets soaked with the toilet water, you see him being brought into a bedroom wearing a towel. Next shot the towel is underneath. The transition of him being undressed is missing, despite the audio being continuous and thus not revealing an ellipsis in the action.
Visible crew/equipment: Two shots after Gaylord touches the boob, you can see a boom mike dip into view.
Continuity mistake: When Greg is talking on the microphone towards the end, it appears in his hand. However, the next time he pops it off the stand, it makes a loud noise that wasn't there the first time.
Continuity mistake: In the first movie, Pam says she received a fax (MCAT scores) from Greg's parents in Detroit. We see in this movie that Greg's parents have lived in Florida for many years.
Revealing mistake: When Jack tells Greg to throw the brick at the RV, when he picks it up you can see it's some kind of spongy material.
Answer: Truth serum doesn't automatically make you speak the absolute truth - all it can do is make you say what you believe to be the truth. If Gaylord believed himself to be Jorge's father, then he would say that under the truth serum, even if it ultimately turned out not to be the case.
Tailkinker ★
Gaylord (Greg) was also drunk when he went on his monologue of spilling "secrets" about others in the room.