Cockroach on the sushi?

I was on a day trip with a couple of friends and we decided to stop at best buffet. Huge selection, something for everyone, right? I’d only been there one before, and while I enjoyed the food, it was noisy and busy…not a problem today, eh?

We go in, are seated and each of us fixes a plate. I set my shusi on the table and went back to get a cup of sauce. Another friend was getting a dish custom made by the chef. I wandered over. Looked good. “Do you have shrimp?” I ask. “No.” “ANY seafood?” I inquire? “No.”

Now, I think, HOW can that be. The custom chef is right next to the sushi bar. I wander over and gaze at all the seafood waiting to be rolled. WAIT. I see something move. It’s a ROACH! ¾ inch, and it’s on the side of the sushi plate right in front of me. I watch as the roach runs across the plate, UP and OVER a piece of sushi, and to the next plate. I call to my friend, who comes over. I point. He says “CRIPES! Thats a ROACH!” Duh. He calls the elderly Asian woman [manager?] over and points at the bug. She calmly reaches over and smashes the bug between her thumb and index finger. No biggy, right.

End of story. The sushi that the roach had crawled up was left out. The plates were not changed, or even moved. It appeared that roaches crawling ON THE FREAKING FOOD was not noteworthy to the staff.

Other than leave, WHAT WOULD YOU DO?