Continuity mistake: When Bridget is getting dressed for her big date with Daniel, her tights are over her undies; later, when he's going up her skirt, the tights are clearly under her big ugly undies. (00:17:50 - 00:26:00)
Continuity mistake: After Mark Darcy and Daniel Cleaver fight in the street and Bridget goes to comfort Cleaver, Mark Darcy flings his jacket over his shoulder as he walks off. You can see very clearly that the white lining of the sleeve, flapping around as he walks. When the camera cuts to his receding back, the jacket is perfectly flat and smooth down his back, and the lining is no where to be seen. (01:12:20)
Continuity mistake: When Shazzer talks about introducing people with thoughtful details, Jude taps off her cigarette ash. Seconds later, she's seen with at least half an inch of ash on her cigarette. (00:16:55)
Continuity mistake: Tom is changing the fascia of his mobile phone. When we first see him, he is holding the phone up to his shirt and the fascia is blue, he then puts the phone down near to Bridget. It then cuts back to Tom and the phone has moved nearer to Jude and the fascia is green. Tom then opens the box in front of him and hold the blue fascia up so it falls out of the plastic wrapping completely, just before a man comes up to ask him if 'he's the bloke who sang that song' he is getting the blue fascia out of the plastic wrapping again. (00:10:50)
Continuity mistake: When Bridget and Mark prepare the blue soup, Mark stirs the soup with his right hand. In the close-up you can see a left thumb holding the spoon. (01:02:25)
Continuity mistake: After Bridget has given the appalling introduction to Mr. Fitzherbet, he comes on stage with the author. Mr. Fitzherbet says "I'll just switch this on" and turns the microphone on, but his voice is being transmitted over the mike before he flicks the switch.
Continuity mistake: When Bridget is searching in the fridge for tuna, she wipes her face, and really big smears of her cooking spread across her cheeks. Then when she goes to answer the phone, the smears are practically gone.
Continuity mistake: After Bridget has chased Mark Darcy in the snow, when the scene initially focuses on Bridget, she has some large concrete barriers behind her, they suddenly disappear from the scene after awhile, just before the big kiss.
Continuity mistake: Mark Darcy is in Bridget's flat and he notices the diary under a folded newspaper and some magazines. In this front shot, he puts the magazines down next to the newspaper and pulls the diary out from under the newspaper. In the next close-up looking down at the table when he holds the diary, the folded newspaper is no longer there. When Bridget walks into the room after Mark leaves, in this front shot of the table, the newspaper is under the diary that Mark had put down. When Bridget comes back from the window, in the close-up looking down at the table, once again the newspaper is not under the diary. (01:27:30)
Continuity mistake: When Bridget is making her resolutions, she says, 'Put last night's knickers in the laundry basket.' But if you read her diary as she's writing in it, she doesn't mention this resolution, it says 'Lose 30 pounds,' then goes on to the third resolution. (00:08:00)
Continuity mistake: In the shot where Bridget goes to see her mom when the mother is selling the egg separator, her sweatshirt strings are crossed, when the shot cuts to her again they are crossed the other way. After the demonstration, when she is talking with her mother, they are back the same way again.
Continuity mistake: When Bridget and Daniel have gone back to his apartment and they are kissing on the floor and he discovers her enormous panties, she is trying to keep him from checking them out again. In one shot the strap of her dress is up over her shoulder, then it's down off her shoulder, then back up again. (00:26:15)
Continuity mistake: When Bridget and her parents are driving to the Darcys' house, you can see that the road already has fresh tyre tracks on it. But once Bridget and her dad switch places, the road ahead hasn't got any tyre tracks.
Continuity mistake: At the tarts and vicars party, Bridget and Mark almost start arguing about Daniel and 'Mark's past behaviour'. Look at Bridget's hair between when she says 'I think he would say the same about you given your past behaviour' and when Natasha calls Mark over - Bridget's fringe changes shape in the three different shots. (00:39:30)
Continuity mistake: When Mark and Daniel are having their big fight, Mark punches Daniel really hard, causing him to fall to the ground. In the shot of the punch Daniel falls face down towards the ground, however in the next shot he lands flat on his back. It would've been impossible for him to have turned around-especially being knocked out.
Continuity mistake: When Bridget is quitting her job and Daniel is trying to convince her to stay, you can see a woman behind him, hanging at the door of his office. She's already half inside, but there was no other person in Daniel's office apart from him and Bridget, and she wasn't seen coming into the office. (00:49:50)
Continuity mistake: While her friends are waiting in the car for Bridget, wanting to take her to Paris, she is standing in front of her flat as Mark walks over. When they talk, the folds in the scarf around her neck very noticeably change in some of the close-up shots of her. (01:25:40)
Continuity mistake: When Bridget's boss at the TV show tells her he wants her to cover the Kafir/Heeney case (the freedom fighter), Bridget is playing with her pen over her right shoulder. The shot then shows her boss is talking to her, but neither her hand nor pen are up - in the next angle of her, she is still waving her pen up by her right shoulder.
Continuity mistake: When Bridget is at the "tarts and vicars" party, her "uncle" Geoffrey pinches her bunny tail for the second time - when he bends over to pinch it he has a straw (or maybe a cigarette?) in his mouth. Just as he does this, Bridget's mother comes along and slaps his hand, he pulls up and there is nothing in his mouth.
Continuity mistake: When Bridget is writing in her diary about the kind of man she must not go for, she is writing on the left page. When the voice over says "And especially must not fantasize about particular person who embodies all these things" there is a close up and she's writing on the right page. Seeing as her diary has a page per entry, not really probable that this would happen.
Answer: Lots of times in book-to-movie situations and even in some remakes, the producers/writers/directors change names or events. It can be because of personal issues, legal ones or it can even be spur of the moment. it can also be unintentional,when they change it without the specific INTENTION to change it. I think in this case it was more likely that the character/or their name didn't have too much of an impact on the story line, so they didn't feel a pressing need to keep it the same.