Can you provide source? I've never seen Apple locking someone out of their account à la Google, only rare dumb user errors in the system clearly designed to effectively prevent them.
This is theft. And it was possible because the thief had her password (by spying on her.) It is known that thiefs do this, changing the password and account details very quickly to lock someone out of their account. Apple recently introduced protections against this, called Stolen Device Protection, which users can enable in Settings.
