In our court system, precedent (an existing ruling by a higher court on a similar case) often weighs heavily in future court cases. IIRC the point of this doctrine is fairness and legitimacy by consistency of rulings.
Its weaknesses, however, include the ability to set a bad precedent. For this reason, our AGs sometimes ignore potential cases if they’re not sure they can win.
In other words, this case might not have been quite the slam dunk the headline would suggest.