Well, if that’s what the owner says….

(and particularly if the owner is totally devoted to it and happens to be the best Prime Minister Britain never had (IMHO), and his grandfather specifically acquired it to protect it, and unselfishly handed its protection over to the state and protected thousands of other sites by introducing the Ancient Monuments Act)

…. then who is better qualified to speak authoritatively on the subject? And who is qualified to ignore him?