A perfect example of the state of our education system. The “adults” at this school were totally clueless and overly reactionary.
With web access at the fingertips of probably everyone involved, I wonder why someone didn't take 30 seconds and look it up... IIRC, the original story was that cashier didn't think the bill was real, and then used the magic pen to check authenticity. The age of the bill precluded the magic pen from working, as the type of paper used when this particular bill was produced doesn't work right with the pen.
This story is several months old, and I don't remember the specifics, and am not going to bother reading the article.