Raptor---you are in correct. I still find it hard to believe that a school would allow an instructor to work there on a third class medical.
And this is still a moot point as on this case the pilot was conducting a photo/video shoot, therefore required to have a second class medical.
Call any FSDO and ask, it is legal. Would a school would hire someone with expired 2nd class or no medical? Itīs up to the school I guess, although I doubt they would. But I wasn't referring to the NC accident, just in general. If you own a helicopter and want to instruct in it, you can do so with a 3rd class medical and even no medical if the pilot you are instructing is the PIC, it legal. Is legal always safe and smart? No.