When Charlotte calls upon the Bennets after Mr. Collins' failed proposal to Lizzy, she is wearing a lace cap under her bonnet as she did after marrying Mr. Collins. Unmarried women did not wear lace caps.
When Mrs. Hurst is playing the piano at the Netherfield Ball, the hand that showing the musical accents, is the wrong hand for the melody. She is accenting the upper portion with her left hand, which would actually be the lower notes.
At the beginning of the Netherfield dance where Lizzy dances with Mr Darcy as the music comes on, the camera is on Lizzy. That shot of her must have been too fast because they slow it down considerably, shown by a lady fanning herself in the background, and Jane further down the line nodding to someone on the opposite wall, both in slow motion.