That's a pretty bold general statement. A lot of conventional wisdom has been and continues to be debunked. I think most agree the method he used was not ideal, but stating that there is a single best approach for every lager regardless of equipment and desired characteristics is a stretch.
It's not bold at all. It's the way the best lagers in the world have been made for at least 100 years.
Please point me to how this has been de-bunked, but don't bother if you're going to send me a link to some dude's blog who fermented one lager warm and his friends couldn't pick it out in a triangle test.