I believe he is correct. The fill operator requires hydros and vis on most of my tanks. I have a pony which I fill with an equalizer hose as needed. Hydro and vis on that tank is entirely up to me.
But if you are having a LDS fill a tank they are governed by the DOT and must operate under their regulations. DOT governs all handling and trans. of scuba tanks. So if you want to fill tanks on your own, fine, but when a LDS does it they are under DOT regs. This all goes back to the comment of just buy a compressor and sell air. To which my origional comment was: Its a little more complicated then that. What do you think, the LDS just made this stuff up. Some one requires them to do this stuff.