Yes because It might be an isolated incident, and I would be doing the restaurant a favor by reporting it so they can take care of the problem on their own.
No way. There are reports you can find online sometimes from the area health departments to see if they make the grade and why they might get marks against them. Some of the same restaurants show to have cockroaches which means they aren't trying their best to keep their places clean.
It may have been an isolated incidence. I try to give people time to remedy a problem. I wouldn't want somebody to automatically assume something about me, what I do, did before getting the facts. So I try to do that to others.