I've seen medium format prints enlarged to quite a size that looked truly stunning and would certainly make that statement ring true, but on the other hand I dont think you can make a judgement like that based on jpg' of scans of prints on a PC monitor. Techically its gone through the digital process as much as any digicam or 35mm image on the web. I read on a webpage about his work that he finishes most of his images in the digital darkroom too. I think there might be a bit more read into what people use to capture the image than the finished jpg you see warrants. I would bet my Nikon it would not be possible to tell a Large format scan and a pic from a Canon 1Ds in a jpg at that resolution as far as detail and tone goes.
Thats not a comment on his pics which are tuly fantastic and jaw-dropping, just an observation on the conservative nature of photographers and viewers of photographs. Surely the most conservative artform medium ever!