Continuity mistake: When baby Jack spills the glue, the stain changes its shape drastically between the first and immediate second shot.
Continuity mistake: When Greg tries to calm down the baby after showing him Elmo, the position of Jack's hands on the crib are not continuous between shots.
Continuity mistake: During the football game Bernard's sweat stains on the sweatshirt appear/disappear randomly.
Revealing mistake: After Bernard breaks the toilet Greg lifts up the baby. From the angle shot from behind, note the baby's fake hair and you'll notice he's been replaced for a very obvious dummy.
Continuity mistake: When Bernard Focker breaks the toilet and blue liquid spills all over, the baby's hairstyle swaps between the first and second shot.
Continuity mistake: Jack says "we have 23 minutes before they cut the cake". Next shot shows the dog and cat sharing a piece of cake. Next shot shows the cake not cut yet.
Revealing mistake: When LJ has his hands stuck to the bottle, you can see a material actually holding his hands on the bottle.
Other mistake: When Jack asks Greg to throw a brick at the RV window and it hits the car windshield Dina and Pam pop their heads out of the RV door looking shocked. In the next scene Pam and Greg are walking into the RV like it's the first time, seems like Pam wouldn't have that reaction to the RV if she's already seen it.
Plot hole: Greg suddenly wears Jack's "breast" during the "monkey business" scene with a crying LJ. But the only time we see it is in the RV which Jack would most likely have kept locked up. How did Greg get ahold of it?
Continuity mistake: When Bernie is on the toilet, his feet go from wearing socks to no socks.
