No you're right in a sense. People have tried to correct me before, and not without reason
Pitch is a musical term. I've heard headphones that measure quite flat down low in FR, but have the dreaded 'one note bass'. So another term that would work would be to say that a good headphone (for me) makes notes audible. But again, I've heard fast speakers that don't have any problems with musical transients, but just don't distinguish notes as well with a bit more melodically complex music. This is number one priority to me, but not for all of course. Sorry for misleading
Put a musician to tab notes with an Ultrasone and the results would not be as accurate.
Anyway, that's what I think at which the 8400 excel. They're quite transparent in distinguishing differences in timbre as well. Very natural sounding cans also, which is a big bonus
If you play single tones at a single pitch/frequency, I don't think any headphone would have major difficulties producing it. This comes apparent, though I think, with more melodically complex music: Some forms of classical, most non-standard jazz stuff, Miles Davis and Frank Zappa...