Or they had a charge sent through them and the poles flipped.

they were fresh out of a bag at the beginning of class, other students used them though. there was plenty of other stuff to mess with so i doubt anyone bothered to bring or use and of the tools required to reverse polarity.

I demand a timestamp.

here you go

there should be a way to see the imbedded timestamp found in phone camera photos.

also i meant /13