Would you publicly correct someone you do not know well?

Some time ago, I accepted a friend request on Facebook from a woman I was acquainted with in high school. We were not close friends, but participated in the same extra-curricular activity and got along perfectly well with each other at that time. She is now a high school English teacher, and while we are FB friends, she seldom interacts with me or comments on my page. Yesterday I posted the following as my Facebook status:

[My name] wishes it were permissible to strangle people who needlessly procrastinate.

She responded by saying “There is no such thing as needless procrastination.” I confess that her comment really annoyed me. First of all, I am aware that procrastination is needless by definition, so I could have just said that I wish I could strangle people who procrastinate. I’m sure she’s waiting for me to say something in defense of my comment so that she can then tell me how I am wrong, correct my usage or perhaps point me in the direction of Webster’s Online. I am not her teenage student and we don’t know each other that well, so we are not on razzing terms with each other the way I am with close friends and family members. Mainly, it bothered me because we are talking about my Facebook status here, not a term paper. Lighten up.

When and if she does correct me, I wish I could respond, “Mary gets an A+ in English, but only a C in Etiquette.” I won’t, of course, because that would only make me equally rude, but it’s tempting.

Questions: Would you publicly correct the language usage of someone that you do not know well? Would it make a difference if the situation was a casual one or one that is more important, such as something business-related? Would it depend upon whether it was an egregious error or a minor one? How would you react if you were the person being corrected?