Ask HN: Apple v/s FBI: why the FBI doesnt give the iPhone to Apple?

I dont get it. Why the FBI doesnt give the iPhone to Apple. Apple installs the Cracking-iOS; creates a backup and restores this to a new iPhone and gives it back to the FBI. Then Apple vaporizes the original iPhone & software. So the FBI never gets the "golden Key" but a backup from the original iPhone. Case closed.