During the Kamikaze Karaoke scene, the black woman with the pearl necklace is shown clapping in the audience, but the scene cuts to her exiting the stage to the applause.
In the first deli scene Genevieve is lunching with her friends and the mustard bottle on their table alternates between opened/closed depending upon the camera location.
There's an establishing shot of the Manhattan skyline showing the Empire State Building lit up in blue and green. Any New Yorker knows that around Valentines Day, the Empire State Building would be lit up all red.