Deliberate mistake: When the girls all order their food at the drive through they get their food but never pay. (00:17:15)
Deliberate mistake: When the Evo crashes into the tanks it jumps into them at height but there was nothing there to make the car jump. (01:17:25)
Deliberate mistake: The balloon llama the chipmunk makes has legs which are completely detached. The pairs of legs should be twisted together. Without this, it looks like the balloon has 6 different ends.
Deliberate mistake: When Layla is having babies and the first one comes out there is already a nappy on the baby. (00:06:45)
Deliberate mistake: When Greg gets murdered and Cindy, Bobby, and Buffy are trying to figure out what happened, you can see the killer is mopping up the blood. However the floor is carpeted so the blood wouldn't clean up, it would smear instead. (00:31:20)
Deliberate mistake: In the scene when the boys jump the car over the bridge and the wheels fall off, after EL and Josh get out of the car you can see that the rotors are fine. However, if the wheels did fall off like it shows, then the lugnuts would be stripped out.
Deliberate mistake: When the limo driven by Gwen (Sandra Bullock) runs over the white picket fencing it's not Sandra's face behind the wheel in the exterior shots. Also, when Gwen runs over the short white picket fencing, in the interior shot from the car the corner of an 'L' shape fence is being hit, then in the front exterior shot the end of a smaller fence is hit. This is cut from a longer sequence, the smaller fencing is seen way in the distance in the first shot. (00:07:45)
Deliberate mistake: Jimmy catches a fly in the air and puts it in his mouth. He then spits it out with great power. You then hear a "Bzzzzz." assuredly made by the fly. How can a fly flap its wings when spit out in that velocity? (00:48:30)