I caught this on a favourite website of mine. WIMP.COM, they post viral or interesting videos. I've seen many speed archers but his technique and where he got it from seem genuine and I can't help but add, effective. While this would be very difficult to reproduce on a compound bow but it might be possible with cams made for that in mind and a proper rest.
Anyway, impressive none the less. I've always been a medieval times aficionado, can you all imagine a company of similarly trained archers riding horseback, the Mongols come to mind. What devastation this could rain down on an army.... And it would keep an even larger army of fletchers quite busy!!!