I think sometimes a company's position on a matter might be different than a person's, and there is a distinction. (I'm not speaking about Jerry specifically, as this is not a discussion I have had with him.)
For example, I think a larger company might be less likely to officially acknowledge burn-in, though you might get someone within that company who has experienced it or believes it's very real. (This is something I can say from experience.)
I know at least some heard the SHURE SRH840 at Can Jam LAX, and a couple had a chance to hear the brand new SRH840 right next to a "burned-in" set I had been using for months (that I left at SHURE's exhibit for them to use). I wasn't the only one who heard a difference. I believe the one I brought (the one more used) was the one they had more available at their table.
As for the "armatures have no burn-in" statement: I don't necessarily believe that, based on my experience, but, as with anything, one guy's experience isn't going to be entirely convincing, and that's not really my goal anyway.