Watching it, it appears that he's capable of reaching 100% yet he uses a cheap 'technique' when he knows he'll have difficulty hitting all of the notes.
Don't compare him in any way, to Eddie Van Halen.
E.V.H uses two hands to entertain the audience, the guy in the video does so to avoid screwing up and thus, cheap.
That'd kind of be like me memorizing (What he does) the line art to Toriyama's art style and reaching great praise (from people who are fans of the show/can't draw/loldeviantart) just by drawing his creations and not really learning much else from art.
Hell, even HE is surprised he got 100% when anyone else who played properly would be like "**** YEAH! FINALLY! YES! (cackle)/Bragrightfullyso" et cetera.
There's nothing bad with double tapping in guitar hero. Why? Look back on Guitar Hero 2. Jordan on Expert. The devs themselves told everyone the solo to Jordan was specifically created to double tap it. So, if you call the double tapping technique a cheap technique, well, playing with one hand and strumming with your thumb is considered a cheap technique as well.
I think he was mostly surprised because from what I can remember he's been working on a dragonforce FC for about 5 months, but REALLY started trying about a month or two ago. I'd be pretty surprised after all that time I got it, thinking "Oh ****... this was... THEE ****ing run."
I wasn't comparing EVN to chris. No ****ing way. EVN is a god. Chris is a gamer. Regardless, I was using more of an analogy with technique, how you can do different style to accomplish a goal.
A very poor example of this would be losing weight. One could go about lifting weights, cardio, exercise, eating healthy as a form of losing weight. Another can go for the whole bulimic anorexia thing and lose weight. It's still accomplishing the same goal, but using a different way.
Now I know that's a poor example because bulimia and anorexia is a bad thing, but it's trying to prove a point.
Regardless, as I was saying, I'd love to see EVN play eruption with one hand. It's impossible unless you have extremely long fingers. You can probably play the closer bits with one hand but having your index on the second fret, while continously tapping the 8th fret is, well, simply physically impossible. Sometimes you just need to do certain techniques to achieve a goal, as with double tapping.
edit: I'm still lost, what's so cheap about the technique? It's like, say, on the nintendo 64 controller someone positions their hand so it's covering the left and middle side so you can use both the analog and the d-pad. Would that be cheap? No, it's just another way to do it.