I can't help but to think that he might have short-circuited the device and thus have damaged some electronic components. Seriously I've accidentally short-circuited some things in my life and so this comes into my mind. Recently I killed the usb-port of my laptop by connecting an usb charger with an opposite poled battery (which I didn't know, as it fit perfectly in the charger and was advertised as a clone...). I got awfully hot in around 10 minutes and was close before a fire, when I finally noticed it, cause it started to smell... I had big luck that I didn't lose more than just one of my usb ports...
I hope, I'm wrong...