The cover picture, the general design and article titles 'FLICKR SHOOTER OF THE MONTH' and 'COMPOSE LIKE A MASTER', I would of thought, are the deal breakers. The guy is probably 17.
But still, what have you got to lose exactly!? If it's an iPad mag, you don't really have to send images much bigger than the average web portfolio size. Just think of it like posting to another web gallery.
Unlike digital images, when you have the negative, it's not difficult to prove you own the image if anything does happen.