We have had no-shows as well but thankfully less common. Always appreciate being told vs just a no-show for sure.
That is mental! Firstly, an estate agent should NEVER be giving you a ration of sh*t. You're the client! That seems crazy to me. Also, one pizza box is definitely not a mess - especially considering you only have a half hour notice.
He didn't remain our agent.

Initially, for our open house, he insisted we "get rid of the cats" and make it appear as if there were no pets living in the house. He also suggested I remove my built-in hanging bookshelves, which were basically floor to ceiling in the living room and full of books, as they were clutter. Collectable books.
Yep. We fired him after the pizza box thing.