Continuity mistake: When Carrie knocks the vase of carnations off the table, the flowers scatter all over the room, but in the close up shot of the table, there are still a bunch on the table, and on the floor around the base.
Continuity mistake: After Carrie rents the car and takes it back, she and Miranda are sitting on the couch talking. As Carrie says something, she turns her head to the right, looking straight at Miranda. When Miranda replies, "Well, that's one option", you can still see Carrie's head in the shot, turned towards Miranda on the right. But then in the next shot of Carrie, she is facing straight ahead and talking in the middle of a sentence. (00:19:30)
Continuity mistake: When Carrie knocks the vase to the floor, it rolls away and settles beside the leg of her couch. In the next shot, it's lying on the floor next to the table she knocked it from.
Continuity mistake: While drinking with Jerry, Sam toasts with her right hand, but a shot later she holds the drink with her left.
Continuity mistake: When Miranda arrives late at her meeting, the position of her right hand is not continuous between shots.
Continuity mistake: During breakfast, Sam twirls her fingers around and gestures at Carrie, then lowers her hand. From the opposite angle it's raised.
Revealing mistake: When Sam and Jerry watch the billboard, a blue car passes by and the driver slows down and stares at the filming.
Continuity mistake: Charlotte's cocktail turns around between shots, check the apple slice. (00:08:01)
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