As a Market Maker, I used to come into the CBOE early Saturday morning after expiration Friday to clear up any outtrades. Was a fun time actually as many people brought their kids in and let them roam the exchange floor playing with the phones and equipment. Old days stories.
I felt bad for the midoffice who had to do that. i felt so bad when I sold some options on Friday (0dte) and booked them as a buy. It took him like 2 hours to figure it out.