Video of the episode shows a woman in underwear riding a white horse, which appears to slip and then fall. As the horse attempts to regain its footing, the rider falls from its back. The horse then meanders through the crowd for a few seconds before the video ends.

The city order says that the footage shows that the horse was scared and concludes that the situation was an “actual threat” to public health and safety — enough to warrant the revocation of the lounge’s business license.

At the news conference, Mr. Gelber recalled his first thought after watching footage of the event: “What kind of idiot would do something like this?”