Ah! I see where the miscommunication happens. They use the word in a particular context.
Here "expert control system" means that it has a decision logic designed by some humans. They sit down wrote an algorithm and said "I think this is a good idea based on what I know about the problem." Compare it with a reinforcement learning system, where they let loose a generic learning algorithm on the problem and then they see how it performs.
In this context "expert control system" doesn't mean that it was expertly designed, or even that it is any good. It just means that humans designed it for this particular problem.
Here "expert control system" means that it has a decision logic designed by some humans. They sit down wrote an algorithm and said "I think this is a good idea based on what I know about the problem." Compare it with a reinforcement learning system, where they let loose a generic learning algorithm on the problem and then they see how it performs.
In this context "expert control system" doesn't mean that it was expertly designed, or even that it is any good. It just means that humans designed it for this particular problem.