Let's say I like to eat at "Deliware" (I borrowed this name from a place in Port Jervis, NY). The place is kosher with a reliable hechsher.
I visit the town, and I know nothing about the community's hechsher standards. I'm wearing my yarmulka, go in and eat there. A frum person sees me go in and walk out with a bag and says, "I didn't think this place was kosher!" I say, "Of course it is. See the certificate from the OU?" And he says, "Oh that doesn't mean anything. It's not under the Va'ad, and any place not under the Va'ad is not kosher, in this community."
Did I commit a violation of marit ayin, here, as I knew nothing about people's preferences?
Let's say Deliware was in my own neighborhood, and I know that people don't trust any place not under the Va'ad, but I know, in fact that because it's under the OU, the hechser is reliable. I even called the OU to verify that the hechsher of Deliware is valid. Is it still maris ayin because my kashrut standards are not the same as the community's?