Re: But who owns the device?
"I’m (obviously) not a lawyer, but I wonder whether the real owner has the legal and moral right ask for help picking the lock. Apple would then have the face-saving option of agreeing on the grounds that they are assisting the owner and not some evil third party, and that this could not possibly set a precedent for government to gain access to everybody else’s phone." -- Mark Simon
I'm afraid the ownership doesn't make any difference. When either the owner or the state has the phone they can legitimately examine the contents. However, the contents are gibberish without the key. The key is ALSO in the phone. But it cannot be extracted by Apple unless that company creates a tool that jeopardises the safety of other customers. Apple, if they are telling the truth, and it looks as if they are, have provided every assistance right up to creating that tool, and now they're asking the courts to dismiss an earlier judgment ordering them to do so.
"this could not possibly set a precedent..."
There is literally no way that this would be possible. For instance, owner asks Apple for help, Apple provides it. FBI asks Apple for help ... Apple say no on the grounds they only help owners? There is nothing any of the parties can do within a court case that will determine (or perhaps even influence) whether or not it later forms a precedent. Remember, precedent does not have to be binding, it can be merely influential.