Of sound mine

In the Washington Post re the Sago mine collapse survivor: Doctors treating the sole survivor Randal McCloy Jr. declined to speculate when the 26-year-old would fully wake up from a medically induced coma or comment on the extent of any brain damage suffered...

Now, I doubt that if he has brain damage that his comments would convey much about it. Wait, oh, I get it! It's just a poorly written sentence. This reminds me of going to get my marriage license and answering the battery of questions they administer before giving one to you, including, "Are you of sound mind?" This poses the question, how would I know and be able to tell them if I were crazy? Isn't that the point, that when you're not of sound mind you have no idea? They also asked if we were related and if we were under the influence. And when I asked why they were asking these questions, they said, "We don't know. It's the law."