I found out the same thing at the end of last summer when I tried to go from 4 to 3. D.F. was also the person that was handling my request.
I had earned 15 points between March and Labor Day, and also was 2nd place at the Winfield Twlight Crit (1 of the 3 ABR races I did). I technically never achieved 20 USAC points, but I also had the 2nd place from Winfield and no DNFs on my resume. I honestly thought he wouldn't have a problem upgrading me. I was wrong and he explained that I simply didn't meet the points requirement.
That said, I got a powertap in late September, have put in lots of quality hours, and am slightly more motivated to prove that I belong in the 3s very soon.