Goofs

The license plate on the hearse changes. When they first get in the car, it is a white plate. When they pull out from her house and head to MD, it becomes a darker blue plate.

When Lloyd is eating a hot dog, he cleans his face with the bun but doesn't get it fully clean. In the next shot his chin is completely clean.

When Harry is driving just before his dream sequence, he reaches over with his right hand to put the photo of Penny in his pocket. In the next shot, both his hands are on the wheel.

When Penny is talking to her father about her trip to give her speech, her purse strap changes from off the side of her chest to right in the middle of her chest.

When Harry gives his beer to Ms. Sourpuss, there is less head on it than when she carries it away a second later.

Fraida Felcher should have been arrested for pulling the fire alarm in a non-emergency situation. She would face up to three months imprisoned and fined $2,000.

Fraida should have been arrested for pulling the fire alarm in a non-emergency situation. This is classified in penal law as falsely reporting an incident.

Somehow, Harry doesn't know that he was adopted after his birth parents died, despite him being white and his adoptive parents being Asian. This seems to imply that both of his birth parents died all the way back when he was a baby. However, in Dumb and Dumberer: When Harry Met Lloyd (2003), he was living with his birth mother, who was still alive, a single mother, and in her 40s. Inconsistencies with that film are not goofs as the Farrelly Brothers do not consider it canon.

Harry's visualization shows that when Harry was a child, he owned a Border Collie named Biscuit, who would lick peanut butter off Harry's groin. In Dumb and Dumberer: When Harry Met Lloyd (2003), he was never shown to have a dog at all. Inconsistencies with that film are not goofs as the Farrelly Brothers do not consider it canon.

When Harry and Lloyd are drinking the embalming fluid, Lloyd's tongue and mouth is blue from previous takes.

When Lloyd meets Penny for the first time he reaches into the fountain behind him to grab some loose change for a meal. He proceeds to put the wet coins into his right pocket, however it is obvious this is a re-take because his pocket already shows a wet patch before he puts the money inside.

Despite a flashback showing Lloyd with a young Freida Felcher back in the 1990s he isn't his younger self.

When Lloyd throws a banana peel in a coffin, the actor in the coffin flinches when he gets hit in the face.

Captain Lippincott shoots through the toilet cubicle door but when he kicks the door open there are no bullet holes in the wall behind.

When Lloyd and Harry mistakenly re-visit Fraida Felcher, it is said the address is Elmwood Avenue in Cranston, Rhode Island. Elmwood Avenue is a main road, not a side street.

After accidentally ending up at Fraida Felcher's house in Cranston, RI, Harry and Lloyd are seen driving west of the I-195 bridge leaving East Providence and entering Providence. Cranston is located south of Providence, not east.

When at the KEN convention, Lloyd's cell phone rings. It says 'Penny', but Lloyd actually has Penny's phone with him (as she left it at home) so he had no way of knowing who it was that was calling him.

One of the inventors produces a machine which can put people's thoughts and memories on to a screen. After Harry's visualisation, he complains that the bed cover in his memory was orange, not the colour shown on the screen. However, Harry had his eyes shut, and was facing the wrong way to see the screen.

For some strange reason Harry and Lloyd didn't know their friend Pee Stainer was deceased until his father told them. Given he died in 1991 three years before the original Dumb and Dumber (1994), Harry and Lloyd should had known he was killed at that time.

Lloyd manages to uses a cell phone without difficulty but as he was in hospital for 2 decades he should have been unable to use a cell phone that easily as they did not exist in 1994.

Lloyd states that he and Harry met Fraida at Pete Stainer's funeral in 1991. How they both met her was, at the the end of Dumb and Dumberer: When Harry Met Lloyd (2003), when she was driving by with her twin sister, Rita, she offered to take them to visit a new girls' college. They got into a debate over which girl they wanted, Lloyd turned the offer down to settle the debate, and Fraida and Rita angrily drove off, splattering Harry with mud.