My girlfriend was perusing buzzfeed when she found a rather hilarious, or what she thought was hilarious, the 21 absolutely valid reasons to get a detention. There were some funny ones, 'go back to whore island' heh, but I saw no humor in item number 12. In fact, if anything, it just illustrates that schooling has become less about education and more about obedience training. If a student calls you out for being undeniably factually wrong: you say 'sorry about that I made a mistake'. You don't send them to detention!
If I had a kid was sent to detention for being right, not only wound I not punish him, but I would also buy him the biggest ice cream cone I could find; and give him a freebie to miss school. Because if my son was sent to detention for insisting that a kilometer is not longer than a mile then he's obviously got a retard for a teacher and isn't going to learn much of anything in the first place.