Great, this is why we have a constitution and bill of rights - he has no legal obligation to speak to them, and of course, if by accident he said something that was incorrect (“I had tuna for lunch” when he actually had salmon) he would be guilty of breaking a federal law, “lying to a federal officer”.
Useful background info: “Don’t talk to the police” video from a law school class https://youtu.be/d-7o9xYp7eE