A long pass from Mitchell Trubisky to Anthony Miller was ruled incomplete on the field. Upon further review, it sure looked like Miller caught the ball but fumbled. However, there was no clear recovery — because the whistle blew on the incomplete pass, no one from either team picked up the ball and it wound up being an official pulling it up.
Very bizarrely, referee Tony Corrente ruled that because there was no clear recovery the ball just went back to the original line of scrimmage. This confused the NBC booth of Al Michaels, Cris Collinsworth, and Terry McAulay, the rules expert who was a longtime former NFL official. After the ruling, Michaels straight up asked McAulay (lightheartedly) if they were making up the rules as they went along.