I get the impulse, but I just think that if the goal is to correct someone--not just to be correct--starting with snark is most likely to be counterproductive.

I get the impulse, but I just think that if the goal is to correct someone--not just to be correct--starting with snark is most likely to be counterproductive. Even if the first comment is actually in bad faith, I consider my audience to be any reader, not just the one I'm replying to, and snark undermines credibility there, too.