Not the first time I've heard that said about this beer... Have not gone out of my way to confirm it.
As to the what's a Nitro question, it is a method of serving. If you look, the tap real black Guinness comes out of is different than what ordinary beer comes out of. That is because the beer is under a higher pressure in the keg, but most of the gas causing that pressure is a Nitrogen heavy blend of N2 (a non-soluble gas) and CO2 rather than pure CO2, which dissolves into the beer and becomes bubbles. Nitro beers are beers that pour like Guinness, with the very fine cascading bubbles... that's because the dissolved CO2 acts differently under the pressure that the Nitrogen causes while it is weighing down on the beer without dissolving into it. Combine that with the extra moving bits in the special nitro taps, and you get a very different beer experience than you'd get from the same liquid pressurized with CO2 and pushed through a normal tap.
