There were a number of posts that really made me wince...and bite my tongue. And no, this thread did not start off on the educational foot (if you will). Go back and look. There is post after post saying this has to be a joke, your teacher is a moron, etc. There was a LOT of attacking of the teacher (not that I don't agree), and you have to remember kid sometimes actually do look to their teachers as a roll model.
The guy, of course, was pushing everyone's buttons on purpose. He pushed, and got the reaction he was looking for. There were a number of good reasons given as to why it wouldn't work...but it was covered in a bit of hostility. So yes, I think biting your tongue (not to anyone in particular) is the best course of action with someone new and young. Again, the average kid is great at turning off the ears when they feel like they're being mocked and attacked. If you can lay down the facts, mow them over with knowledge, and not get hostile about it then it's going to have a much great effect than someone saying "You must be joking, if not, you're crazy and your teacher is dumb!" (I know that no one here said exactly those words, but it's exactly the tone given through the first posts). Just look at option A and option B, as think of how you would have reacted as a kid.
I didn't jump in as there were enough people beating that horse. I have gone on plenty of rants myself. This is just food for thought for everyone...myself included. As this wasn't real anyway, there wasn't actual damage done. What needs to be taken away is the right way to act if it comes up again and it is real.
Just think of this as me playing Devil's advocate. I really wanted to say a number of things that were said, but held off. After this wrapped up, I wondered how this thread would be different if people posted in a calmer and more respectful manner. Given the guy, it might not have been different; but I think if given a real kid with a real situation, it would have.