Does live rock remove nitrates?

[Aquattro]

I've always believed, and my tank has always followed along with the idea that live rock, in sufficient quantity, removes NO3 from the water column. My understanding from the various articles I've read or threads I've seen posted is that the anaerobic areas within the pores of the rock convert nitrate to free nitrogen gas that is then removed via regular gas exchange at the surface of the water.
Now I noticed a comment by another experienced reefer that they didn't think this happened with rock, and after a brief discussion, I'm confused. (Yes, again).
Is it everyone's assumption that live rock performs this function or not? Any written confirmation either way that can be linked to?
I've always had 0ppm NO3 in my tank, regardless of water change schedule. I've usually had a fish load on the light side, but still. If the rock wasn't removing it, then what's going on? My assertion that NO3 was 0ppm is based on various hobbyist test kits, frm Hagen to Salifert, over a span of 6 or 7 years.

Thoughts/comments?