I'd argue that the unethical bit is knowingly publishing incorrect information, especially in an educational setting. If there's a chance that someone learned d

I'd argue that the unethical bit is knowingly publishing incorrect information, especially in an educational setting. If there's a chance that someone learned deliberately false information that they will then attempt to apply in a practical setting, then you're effectively sabotaging them. He did say that it was obviously wrong if you had been paying attention, but what if you missed a class or two?