Even though he might have not done anything illegal, of course Apple might come after him.
Usually you can only go after the leaker or anyone republishing the IP. Simply having access to it isn't a crime. Perhaps they could issue some sort of takedown notice for the schematics.
Not a lawyer, but I seem to remember that trade secret law in California at least covers information you know should be secret. So if I'm remembering correctly, information derived from leaked docs would be subject to trade secret law.
IANAL also, but how would it play out in practice? Provisions in law are different to what can happen in practice. Perhaps enough damage has to be proven in order for remedy to be handed down?
And is it criminal violation, or just civil? And if civil, if the violation happens overseas, not much can be done in practice, right? I don't know much about American IP law.