Continuity mistake: When Greg places the luggage on counter in his apt to measure it, the front pocket double zippers are closed at the bottom of the left side. When Pam comes home and he describes the birth, both zippers are at the top center of the pocket. (00:02:20)
Continuity mistake: At his apartment, when Greg walks over to the laptop things on the desk change position, such as the bowl, which goes from being two feet to the right of the laptop, to directly behind it in the close-up, then back again. (00:02:30)
Continuity mistake: Whilst speaking to Pam at their apt, Greg lifts the luggage off the counter. In the first shot, the front zippered pocket faces him, but in the next shot it faces the opposite way - away from him. (00:03:20)
Continuity mistake: When the airline agent bumps Pam and Greg to first class, she holds out the tickets, with white at the top. In the next shot facing Greg, as he takes the tickets, the yellow is at the top. (00:05:00)
Continuity mistake: In the scene where Pam and Jack do the shortstack rhyme, Greg suddenly joins in and says "Ba ba ba ba ba ba ba." At that moment, Jack is looking at Greg. Then in a split second, when the shot changes to the other side of Jack, Greg, and Pam, Jack is looking at Greg's hand, then looks back up at Greg. (00:07:10)
Continuity mistake: When demonstrating the baby's "sign language", Jack puts a series of cards on the table. You see him start to put the "poop" card down in one shot and even hear it hitting the table and being moved slightly in the next shot. But after those shots, you see him put it down again. (00:09:05)
Visible crew/equipment: In the scene where Greg is leaving a message on his parents answer machine about going to their house in the Byrnes' motor home, you can see that it is just Stiller standing in front of a blue screen, obviously they wanted to add the scene in after shooting had finished. (00:11:55)
Continuity mistake: When Pam and Greg step into the motor coach nothing is on the counter between the sink and stove. However, in the shot facing Dina there are groceries right beside the sink, at the edge of the counter, including a box of Orville Redenbocker's microwave popcorn. (00:12:20)
Visible crew/equipment: As they start out on the trip, when they are showing Jack & Greg up front, you can see in the window right behind Greg a reflection of two crew members wearing sunglasses. They stay in frame for about 5 seconds. (00:13:21 - 00:13:26)
Visible crew/equipment: After Jack says, "Only the captain gets to make announcements, Greg," in the next shot of Greg the boom mic and pole are nicely visible over Jack's reflection in the window, to Greg's right. There are two other shots of Greg at this angle - one previous and one following, but unfortunately the equipment is not seen. (00:13:25)
Continuity mistake: When Jack and Greg are in the motor home near the beginning of the movie, Jack is talking on the intercom mic to his family in the back, then puts it down when he is finished. But, in the following shot that shows Greg talking, you can see Jack's reflection on the window, showing him still talking into the mic. (00:13:30)
Revealing mistake: When they show the bus with the college girls going by, as they pan over the driver, you can tell there is no door on the passenger side. You can see all the way to the ground and road of, what appears was a blue screen background added. This is made even more obvious by the fact the girl driver is not wearing a seat belt, is supposedly flying down the highway, and if this really was a huge hole in the side of the bus, it would be extremely dangerous as she could fall out. There also seems to be some sort of white mattress pad right next to the driver. (00:14:05)
Visible crew/equipment: While passing the frat-house bus, in the close-up, as the two girls are about to flash, the reflections of the camera and two crew members moving on the crew's vehicle are visible on the glass window. (00:14:15)
Continuity mistake: When Jack and Greg honk the horn at the bus with all the girls, not including the driver, there are four girls looking out the windows at the front half of the bus. These girls have a purple bra, a pink bra with long shirt sleeves, an orange/ pink bra, and then a dark green bra. After two girls flash, the girl in the pink bra (#2) with long shirt sleeves, and the girl in the dark green bra (#4) are suddenly at the back half of the bus. Look at the lettering on the bus "Manassas University." In the 2nd shot, they are now after the "Y" in "University." (00:14:15)
Continuity mistake: In the motor coach, when Greg takes the milk from the fridge, the window shade behind Little Jack keeps moving up and down between shots. (00:14:40)
Continuity mistake: When Greg accidentally drinks milk from little Jack's nutrition supply, he spits out the milk and it dribbles down his chin when Jack tells him it's from Debbie's left breast. Greg wipes some of it off, then In the next shot, he turns around and all the milk is gone - the shot changes so quickly there wasn't enough time for Greg to wipe off the milk. (00:15:25)
Continuity mistake: In the scene where the two sets of parents meet for the first time on the island, Bernie hugs Greg leaving his sweat mark on Greg's shirt which also looks wrinkled. This changes to there being no wetness at all, some wetness and then very wet again in between shots of him. When he enters the house, his t-shirt is totally smooth and dry. (00:21:25 - 00:23:20)
Continuity mistake: When they all first arrive at Roz and Bernie's, Jack brings LJ over in the stroller. As Bernie babbles, "Bazooka, bazooka," and LJ starts crying, the stroller's orange flap (between LJ's legs) is attached to the front harness around the boy's waist. In the previous couple of close-ups of Little Jack, the orange flap hangs down between his legs. (00:23:25)
Continuity mistake: When Greg does damage control in Roz's office by hiding things, the height of the table is about Greg's waist level - also note the wood paneling trim. In the previous shot, as Greg surveys the room, the table is a foot lower, which is also seen in other shots including when Greg enters the room, after the football game, to check on Jack and the table height is level with Greg's thighs. The entire table was deliberately raised in the close-up. (00:27:00)
Continuity mistake: When Greg goes into his mom's office to quickly put away all the sex toys and objects before the Byrnes come in, on the dresser, to the left of the door, is a statue and a shell. In the next shot, after Greg has shoved the statue behind the desk, the shell has now moved from the left to the right. There is no time for this as it is shot as a "continuous" sequence. (00:27:13 - 00:27:19)
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.