(:edit conflict) No, and as recently pointed out again on RS, sources are considered on a case by case basis, on a number of criteria. In this case, the source matches the claim because a language expert is verifying graffiti. (If we wanted to verify a climatological claim, we'd want a climatologist. If it was a new scientific theory that changed everything accepted about climate, we'd want more than one climatologist, peer reviewed journal. Etc.)-