In a case like this, they would just request the information through a legal procedural called "discovery" in which a party is required to turn over requested information relevant to a legal matter to the opposing party.
In short, it doesn't matter if they don't have EULA or technical access to the data.
They would never snoop on a personal device - the risk of loss of user trust and pr has to be immesurably greater than any potential benefit. Maybe he used devices owned by Apple to work on his company.