I left a comment on When do you check if you lose.

This question does not show any research effort. The first Google result for "prosperity mtg" has a ruling that says "10/4/2004 If both players run out of cards during this effect, the game is a draw." – Rainbolt Feb 14 at 21:06

The response I got was this:

I realize that now, but thanks for pointing out my stupidity and yours or lack there of, SENPAI – eric Feb 14 at 23:57

For those who may not know, referring to someone as senpai in this way is a form of sarcastic admiration. That sarcasm, plus a jab about someone's stupidity, make up the entirety of the comment. Comments really don't get any less constructive than this.

I flagged the comment as "Not Constructive", but the flag was declined. Was raising a flag the wrong thing to do? Did I raise the wrong type of flag (something I've been known to do in the past)?