You misunderstood stanz. What she found humorous was her post #15 (or whatever the number) not the despicable act.
"It" is "the stunt".
But even assuming arguendo the "it" is the ill-considered wisecrack of #15, we must then take her word for it that "it" -- the wisecrack -- was not "a nice thing to do".
Which is it, StarFan? Or does it all depend on what the meaning of "it" is?