The establishing shot of the hospital shows the sign for "Guy's and St Thomas Hospitals Trust" which was the name of the organisation when the film was made in 2001, but Guy's and St Thomas did not become a single NHS Trust until 1993, whereas this film is set in the winter between 1989 and 1990.
While the lads are caught in traffic in Vince's car leaving London they are passed on the other side of the road by a white Citroen Berlingo Van, a vehicle not introduced until 1996 (with this particular one having 1996 registrations plates), 7 years after the film is supposed to be set.
The fluffy head of the boom mic is visible at the top of the screen during one of the flashbacks to young Jack Dodds flirting with his wife-to-be (although at this point he has only just met her; they seem to be cutting runner beans, or something). This is visible even when displayed in the correct aspect ratio of 2.39:1.
When the chaps make a stop for lunch in a pub on the way down to Margate, Vince tells Lenny'it's a quarter to two'. Later, once they reach Margate, they drive past a municipal clock, with the hands set at five-and-twenty to two (13:35).
When Vic first takes Jack in to the bar and orders a double whiskey, the publican, Bernie, pours two large drinks, but thereafter the amount of whiskey in Vic's glass halves and doubles between takes until the end of the scene.
During the sex scene between the younger Vince and Sally in the the camper van (which is shot from the side), Vince pulls off Sally's knickers but, a few moments later, when Sally tilts her body towards the camera she is wearing a different, smaller, pair of knickers.