(at around 1 min) When Samantha attempts to have sex with the "Mr. Cocky" for the second time, nude underwear is clearly visible.
During Carrie and Big's lunch at Eleven Madison Park, the second couple to be sitting behind Carrie (an hour into the lunch) the woman's salad appears, disappears, gets served, disappears, etc.
Samantha says, "Black widow spiders bite the heads of their mates when they're through". Actually, it's the female praying mantis who tries to bite off her mate's head after coition (smart male mantises fly away in time). The black widow spider just stings and poisons her mate.