Goofs

When the girls come out of Chuck's bedroom to get the Gatorade, the clock on top of the stove reads 4:04. When they go back into the bedroom after getting Gatorade, it reads 4:02.

When Chuck meets Alex in the supermarket, she is wearing her glasses. In the next shot, she isn't.

When Chuck is talking to Alex in the pharmacy, his necklace goes from being over his undershirt to under it several times.

In the rooftop scene with the guy stuck in the chimney, a large cable hanging from a telephone can be seen directly in front of the Empire State Building. It disappears when the building is seen between the his legs. The director had it digitally removed from the shot, but didn't want to pay to have it removed from the other ones.

When Chuck and Larry are in the cab in Canada, Chuck's necklace appears and disappears between shots.

Chuck and Larry enter the burning building without using their face masks and air supply. No firefighters would do that, and they wouldn't last long breathing that air.

The scene where Chuck and Larry extinguish a fire at a diner caused by an employee smoking marijuana, Chuck uses a fire extinguisher to spray that employee in the face. The extinguisher has a cone shaped nozzle which is indicative of a carbon dioxide extinguisher. This type does not leave any residue like in this scene which leaves a bunch of powder.

Larry makes a big deal about being Catholic when arguing with Larry about their 'wedding'. The Catholic Church does not allow or condone gay marriage so his concern is irrelevant.

In the cab in Canada, as Chuck and Larry are fighting with the cab driver, you can see that the gear shifter is in the park position as they are supposedly moving in the car.

When Chuck sits on the kid chair and it breaks, you can tell the side of the chair was noticeably pulled with a wire (which was later painted out.)

When Chuck & Larry are joking about eating the rat and the floor falls through, the entire building and everything in it is burnt, but the papers that fall to the first floor are all clean and unburnt.

In the firefighter scenes, the firefighters are seen riding on the back of the ladder truck. Firefighters have been banned from riding on the outside of the trucks for decades.

When Chuck thinks he is putting a pillow case on his pillow and Larry says that's his underwear, you hear Chuck say 'NO!' but his mouth doesn't move.

When the fireman soap is falling down (first time) you hear the man saying "NO!" but his mouth doesn't say that - instead he says something like "bla bla".

Larry resorts to naming Chuck as his life insurance beneficiary because Larry is concerned that the dangerous nature of his job may result in his untimely death and leave his kids alone. So he counts on Chuck to take care of the kids in case he dies. The problem is that Chuck has the same dangerous occupation as Larry, in the same firehouse, on the same shift and engine.

Cincinnati spelled incorrectly as "Cincinatti" on the picture in Chuck's house.

When they first arrive at the fire where they rescue the fat guy, you can see that the firefighters are just aiming their hoses randomly, not at the fire. One is even spraying the side of the building where no fire is even visible.