Update
Short story: After another 2 hours on the phone Monday, another supervisor fixed the award as a single award.
Long story: After I called back, the AAgent said the award desk said the award was invalid because it exceeded MPM+25%. I asked them how they got that mileage (since it doesn't). After 30 minutes, they and several other people consulted were unable to find where the 8400 miles calculated came from, other than from a note that a prior agent made. After some time consulting with the rate desk, was again told that it was due to AS being the governing carrier and they do not publish a fare HNL-PTY. I asked the agent to look up their rules to who is the governing carrier, and she finally determined it was AA. She was thus unsure why the rate desk told her it was AS. After another while on hold, she brought up the "most direct routing" wording again, but again after searching and consulting several people, was unable to determine what qualifies or disqualifies as a "most direct routing" and I showed her an itinerary that was almost identical to mine for sale by AA.
She thus handed me off to her supervisor, who was also unaware of the MPM+25% rule. He again told me the award was invalid because it exceeded MPM, and after I told him of all my prior conversations, spent about 30 minutes looking in his manual to find the 25% rule. Then he seemed confused and apparently had others looking into why my award was not valid, especially because the rate desk had the "final answer" of splitting the award into 2 awards based on route mileage that was blatantly incorrectly calculated by a prior agent, and obviously had not even looked into the actual itinerary. In fact, there was apparently a note on the itinerary advising AAgents to NOT book the itinerary as one award because it exceeded MPM. So after being on hold again for some time, he said he and whoever else was helping him could find no reason why the first person had split the award, and said he would have the computer reprice it. When he did that, it obviously came back to the correct mileage.
So finally after about 6 hours on the phone over 3 days, and several more hours of learning AA award rules apparently better than almost all the AAgents, the itinerary is back to what it autopriced as. The best part is, I probably won't book this itinerary as the timing is not what I want, and I found better flights.