Continuity mistake: In the scene where Carrie and Miranda are eating cakes outside the shop, talking about Miranda having to be supportive to Steve about his basketball competition, keep an eye on Miranda's cake. She takes bites out of the cake and then when it is down to the last bite, the camera shows Carrie, then shows Miranda again with the cake suddenly full.
Continuity mistake: The episode 'Attack of the 5 foot 10 woman' in season three, when Charlotte is afraid of the sauna. She is running into the sauna with a towel wrapped around her waist. The towel comes loose and is nearly falling off - but in the next shot it is neatly tied around her waist.
Other mistake: When Carrie, Samantha and Miranda step outside of the hotel so Carrie can have a cigarette, she takes a couple of draws then throws it down on the step. She tries to stub it out with her shoe by twisting her foot on it but she (the actress) accidentally kicks the cigarette down the step, so she has to just pretend to still be stubbing it out.
Factual error: Throughout this episode, when Carrie talks about the functions of the left vs. right sides of the brain, she has them backwards. The right side of the brain is the creative side, the left is the logical one. Apparently, the writers liked the idea that the "right" side of Carrie's brain would ultimately lead her to do the "right" thing about Mr. Big, but that's not the case. Rational decision are made with the brain's left side. (But then again, Carrie never was very rational when it came to Mr. Big.).
Continuity mistake: When Samantha and her date are in the health food restaurant, she orders wheatgrass shots. The waiter pours them, filling the cups to the brim and then sets one on the table in front of each of them and we see again in a close up that they are both full up. Yet when Samantha picks up hers to drink, the liquid level has gone down a little way.
Deliberate mistake: Whenever Charlotte and Trey are shown sitting on the therapist's couch, Charlotte is considerably taller than Trey. They are both sitting on exactly the same surface, so there is no logical reason for this. In reality, Trey is actually taller than Charlotte. She should not be sticking up higher than him on the couch.
Continuity mistake: When Carrie and Shaun are laying on the floor of her bedroom, she has her left hand resting on her chest. But in the very next shot; her left arm is laying across her stomach, and her left hand is curved around her right waist. No time has passed in between these shots. (00:12:25)
Plot hole: When Charlotte runs out of the restaurant; her male friend is still chasing her, and you can see him follow her out the door to the sidewalk. But then Charlotte falls in front of Trey's taxi, and Trey gets out to help her up and they meet. Meanwhile, where is Charlotte's friend? He would have still been outside, have seen her fall, and surely would have ran over to help Charlotte and see if she was OK. Yet we never see him again after she falls, and he virtually disappears from the scene. (00:22:30)