^ What the hell are you talking about. That's a tight riff. If the 'tempo slip' was inexcusable why was it done the same way on ever repetition of the riff and why did the drums follow it exactly? It's just groove, ffs. The riff wouldn't sound as good without it.
The drums DON'T follow it exactly. Bonham does the same thing over and over. Mabe it's because I've been trained as a percussionist, but the way it sounds when he tries to croud that many notes into one little space sounds very annoying and odd to me.
Besides, they do it differently in the How The West Was Won.
