To take a slightly different example, my DM was occasionally acutely telepathic over long distances, but only when someone close was in some sort of extreme stress/distress. I knew of it only twice in her lifetime, but each time she had dreamt exact details at the time it was happening. So her ability - and she was a hyper sensitive type anyway - could never have been proved under conditions.
This has happened to me. I dreamed my mother's death, and the condition she died of, before it happened. I knew when something was seriously wrong with my grandmother. I called from America when I somehow sensed she was seriously ill.
Some people might say that was psychic, spooky, second sight, whatever. The way I see it is that I knew these people very well. I'd clearly, obviously unconsciously, picked up on tiny little indications that something was not right. And this manifested itself when I was at a distance from those people and my brain had processed it, also unconsciously, in sleep and seemingly uncanny premonitions.
The dream about my mother was, admittedly, a good two years before she even showed the first signs of illness - and her illness progressed remarkably quickly, a mere five weeks from the first sign something was seriously wrong and three weeks from her diagnosis. But her cousin had just died of the same (very rare) condition, we were close and her death shook me, and naturally my worst fear was losing my mum in the same circumstances.
That this fate did actually transpire was nothing more than a tragic coincidence. I, personally, don't believe my 'sixth sense' derived from anything other than earthly means, and the bizarre human unconscious behaving as inexplicably as it generally does.