“Apple can’t decrypt your iPhone: Why it matters “
Of course they can. If they couldn’t do it, they would have told the judge that, and avoided the expensive legal battle. Instead, they said they wouldn’t do it (in that case).
More on the case- they thought the guilty plea would get them off the hook. It hasn’t, yet:
Feds still want Apple to unlock iPhone even after guilty plea
http://www.slashgear.com/feds-still-want-apple-to-unlock-iphone-even-after-guilty-plea-02412475/
No, you are wrong about what Apple told the judge.
Apple actually told the judge that they could not unlock or decipher the more than 90% of iOS devices that are currently using iOS 8 and iOS 9, but they can unlock the less than 10% of iOS devices that are still using iOS 7 or lower. That is not the same as saying "of course they can unlock all iOS devices," as you claim.
They did say that they would not unlock the older devices (which this case did involve) because that would make a differentiation between Apple customers who had opted not to upgrade to the newer iOS. It would also set a bad precedent that the government could require a third party to expend time and money to serve the government's interests, when the government had not shown there was anything on the device of probative value, and they were merely wanting to go on a fishing expedition.
Apple might have just scored some points with users but might have also further cemented the government's stance against encrypted devices. Responding to a Brooklyn federal judge's request for input, Apple revealed that it is impossible for it to unlock an iPhone or an iPad running iOS 8 or later due to stronger encryption methods. That said, it does admit that it can technically unlock devices running an older version, including the one involved in a current court proceeding, but advises the judge not to open that can of worms. SOURCE