I didn't create the "rule", I just know it exists. I remember a game a few years ago where somebody bunted to break up a no hitter late in the game and the manager got real hot.
This is correct. An "unwritten rule," since the bunt in that situation is done, not to
win the game, but just to break up the no-hitter. The opponent is
expected to try to WIN the game, but if someone
bunts in the 9th inning, presumably with nobody on base, it's considered a really sleazy way to just avoid the stigma of a no hitter. At that point, you need a real hit and not a "trick play." Gotta Be a Man.