Yes, I also saw several news outlets reporting "a man claimed that a boy is tapped in a balloon" and "a man claims to have been unable to slow his Prius when traveling at 90mph". If you hear "someone claimed to..." and assume it's true, then that's your prerogative, but I don't take that position.

The first, yes they investigated and later reported that it was a hoax. The second, they are still collecting conflicting data and are waiting on a conclusion. I believe this story is at the same point - there's a claim, someone is going to investigate, we may or may not know the truth shortly.

I suspect it's rocks, but acknowledge the possibility that it's not, and am awaiting further investigation. I don't believe it's true just because I read someone claimed it was true on the interweb, but maybe that's just me.