I understand why it sounded like that, but I really don't think people do it intended as shibboleth, but because it is more effective. I mentioned what sounds

I understand why it sounded like that, but I really don't think people do it intended as shibboleth, but because it is more effective. I mentioned what sounds like potentially a shibboleth aspect reluctantly, with a sense that might be misleading. I should've characterized it better. Maybe less like a shibboleth, and my thought was more like "We can have this higher-bandwidth communication, if I don't drop the ball" or "This is a person from my hometown or who shares my native language, and it would be stupid to use a different language, or not fallback to my hometown accent".