The timing of computer search warrants when it takes years to guess the password

Article note: The argument that making a copy of someone's machine and trying to hack it forever [Is | Is Not] a violation of a time limit on a search warrant is interesting. I'm a little curious about some particulars of this case (eg. they worked on a copy, but iPhones are supposed to have a hardware key to prevent exactly that?) There are many suspicions about certain agencies doing drag collection and storage for later decryption, and there are lots of procedural ways that already exist to be allowed to keep hackin' on copied data, so perhaps this is really just a narrow authority spat between a judge and an agency?