Why would Apple want to share its proprietary designs with a *competing* company already involved (as either the thief or victim) in several industrial espionage incidents when it can just use a "neutral" (not to mention the largest) contract fab like TSMC?
This naively assumes that nobody at the "largest" contract fab is willing to sell a couple of designs to whoever is interested in them. But they are ready to spend millions on chasing that dream.
Apple should understand that once they release something to another company that "something" is instantly copied and sold to the highest bidder. Their only hope would be to keep the high level design in Cupertino and send only the lowest level stuff to be manufactured. But if they want to take this road they can do it already - and as some people commented earlier, they do just that.
As it seems, though, Apple developed a case of corporate paranoia. There were signs of this disease before, but now Apple openly proclaims that "everyone is stealing from us" and such things. They need a head doctor.
What the eye doesn't see. The heart doesn't grieve about.
To Apple, Samsung is clearly infringing on their IP. A change is in order.