Wrong,
AMA liability insurance covers you pretty much anywhere you want to fly (with few exceptions that are listed), as long as you follow their guidelines (i.e. no bystanders beyond a certain point and so on).
I didn't read in his post anywhere where he said he didn't have AMA. I would definitely suggest to anyone to get AMA insurance. If something goes haywire, these things can fly for miles before they come down--and at that point can hurt someone or someone else's property. You don't have any control over people miles away from you!