Continuity mistake: While at their friends' place, Carrie holds her glass of wine wth her index finger extended over the bowl. A shot later the grip has changed completely.
Continuity mistake: When Charlotte arrives to visit Sam, the doorman is facing straight and turns his head to the left. A shot later his whole body has turned to the left.
Continuity mistake: At the party, when Samantha is talking to Sean, she holds her glass at breast level, but when his wife arrives it is at mouth level.
Continuity mistake: When Carrie and the guy kiss at Central Park a man in a gabardine walks by fast but disappears in the following shot. Then he reappears seconds later walking slowly.
Continuity mistake: When Peter's wife asks him if Carrie saw his d*ck, he has a mug in his left hand. A shot later it disappears and his arm is lowered, only to reappear in the following shot.
Continuity mistake: When Carrie bumps into naked Peter, his right arm is lowered or raised scratching his ear, depending on the shot.
Continuity mistake: When Carrie is at her friend's place in the Hamptons her left arm is either on or off the table depending on the shot.
Answer: I'm a long-time fan of the show, having re-watched it many times, and I definitely remember slightly different dialogue at the end of that episode than what's on my DVD. I'm afraid I have no idea why this change might have been made or any other info, but you're not insane.
Purple_Girl