Is there a trademark exception for being a kid? No.
Is there a trademark exception for "same shape as different colored component of product"? No.
Now, had he sold a white case without the logo, that would be a totally different story...
That said, I'm not sure his products can be described as "counterfeit", because at no point did he claim they were official Apple products or mislead customers in any way. Absolutely everyone who bought a case off him will have known that it was a non-Apple product designed to enhance the aesthetics of an Apple product.
(Again, without knowing about the laws, perhaps legally this is classed as "counterfeit" anyway, but not, in opinion, outside of a legal situation.)
He probably would have gotten away with it if he had changed the labels, but I doubt that was technically feasible anyway.
On the other hand, you could argue it's not interesting enough to be worth writing - but the reason it's of interest is because this kid was of interest when he found a clever way to make money in the tech area, plus any story involving a company such as Apple and a legal case is sexy, partly because it offers an insight into how they might approach other legal issues in the future.