As others have mentioned, the school should have a compliance officer that would be in charge of clearing this situation in relation to NCAA rules. Seems weird that the AD would push the question back to the athlete, unless he was caught off guard, didn't understand the question, or was just being lazy.
On a personal note, when I was college, I was the #1 player on my NAIA team and had a small athletic scholarship (I think it was $1,500 per semester). I also had a part-time job working directly for the athletic department at $7 per hour, plus benefits. My job consisted of managing a team of student workers that performed game day operations for basketball and volleyball events. Outside of these events, I would also fill in for professors in teaching PE classes when needed, was an assistant director for the athletic camps in the summer, and other assignments as needed by the AD and coaching staff. It's the best/funnest job I ever had, and all of this work was legit.
However, what was odd was the Spring time, when the tennis season started in earnest. The assistant AD was the main person I reported to, and he was also the tennis coach. Once the dual matches got started, my athletic department job consisted mainly of stringing racquets for the team, driving us to matches, and practicing my serve!!! That's right, sometimes I would report for work, and my boss would say "I don't have anything for you to do, so please take this basket of balls and go hit serves for a couple hours!"
I can't believe I got paid for that, and I'm sure it was some sort of rule violation... but that was a long time ago ('91-'95), and it didn't seem like a big deal. (Besides, it's not like we ever contended for a national title. But my serve did get pretty solid!)