Continuity mistake: Just before Helen gets hit by a car, it is pouring with rain, and she and James are soaked, although when she is about to cross the road, the rain has stopped and they are both suddenly dry. (01:23:55)
Continuity mistake: In one scene when Helen has short hair, she is talking to Gerry. As the camera cuts between her and Gerry, her fringe alternates from being behind her ear to hanging down her face. (01:04:05)
Factual error: At the beginning, when Helen is running for her train, the station signs clearly say Embankment. However the type of train that she misses/catches is specific to the Waterloo & City Line, which only runs between Bank and Waterloo - it doesn't go anywhere near Embankment!
Continuity mistake: When Helen arrives home after being sacked (in the version where she doesn't catch Gerry in bed) he calls out to see if it's her. She replies "No, it's your bit of stuff. Wednesday, shag day, remember?" However it's been made clear from Helen's attempted replacement of the booze she took from work on Friday that it's actually a Monday. (00:14:30)
Continuity mistake: When Helen catches her boyfriend in the act, we see very briefly that there is a gap between the bedside cabinet on which the radio cassette player is sitting and the wardrobe. This is more clear when her boyfriend switches off the music. Later when the other Helen comes home and her boyfriend leaps onto the bed to hide the earring we see they are much closer. Granted Helen now has two parallel lives but that can't explain the change. (00:11:55 - 00:15:20)
Suggested correction: The fact that the "other Helen" is a different timeline easily explains the difference. In one timeline the cabinet is closer to the bed than in the other. There'd need to be evidence of the gap being different in the same timeline for it to be a continuity mistake.
Continuity mistake: When Gerry spots Helen at the post rowing activities he peers through the window. We can see 3 glasses from his side, one half pint glass partly hidden by the window frame and 2 pint glasses visible through the pane beside the one he is looking through. The shot from inside only shows two pint glasses in different positions. (00:46:20)
Continuity mistake: When Helen's friend arrives in the bar to find her drinking alone, the Grolsch bottle is empty but when she gets up close and starts talking to her it is suddenly half full. When the shot moves in closer the cigarette packet also moves. (00:22:10)
Continuity mistake: On the train when Helen is speaking with James, her hair goes from being behind her ear to being in front.
Continuity mistake: When Helen kisses Gerry before she leaves for work, we can see considerably more of the face of the alarm clock than we can a few seconds later, when he "wakes up" and takes the phone off the hook even though the camera angles are the same. (00:00:55)
Continuity mistake: In the shot where Helen is getting drunk alone in the bar, she is seen swigging a beer from up close, then far away, then close again. The beer switches from her left to her right hand. (00:18:15)
Continuity mistake: When Gerry reveals to Russell that Lydia may be pregnant there is a shot when he is leaning his right cheek on his clenched fist. When the shot changes, his jaw is cupped in his hand. (01:08:00)
Continuity mistake: The second time Gerry is discussing his problem with his friend in the pub we see the level of his friend's pint goes down and back up between shots without it having been touched. (00:36:55)
Visible crew/equipment: When James invites Helen to spend the evening with him and he hangs up his phone and talks to another lady, a microphone is visible moving under the ceiling.
Continuity mistake: There are two scenes when the different shots show blond Helen's hair first hanging in her face and then not in her face. One is in the diner with James drinking milkshakes and the second is when they bump into each other outside the restaurant when Helen has gone to track James down to find out why he hasn't called her. An even more glaring problem with the diner scene is that in one shot from behind her, Helen is pushing her hair behind her ear and the very next shot, which shows her full-face, her hair is still hanging down in her face.
Continuity mistake: Late in the film, there is a scene with James & Helen at night, in the rain on a bridge. The bridge is Albert Bridge. James is standing with his back to Cheyne Walk (north side of the Thames) talking to Helen. When she replies she is also standing with her back to Cheyne Walk.
Continuity mistake: In the first scenes, Helen and Gerry live in an 2nd/3rd floor apartment as Noted by Helen going up and down stairs. But on the later kitchen scene, Lidia shows up by the kitchen window.
Continuity mistake: In the sex scene, the positions of Gerry's hands on Lydia's back keep changing in each shot. The movie was edited for a PG-13 rating in America, this mistake is only in the uncut version.
Continuity mistake: At Helen's desk at her new office a note pad isn't present first shot, then appears next shot.