I personally book approximately $25 thousand in AA tickets each year, none of which are non-changeable. Most are non-refundable and each time before I hit the purchase button on the website, I recheck my dates, flights, and all other information twice to make sure I don’t end up with an unforced error. I don’t expect AA, even with my status, to save me in the event I screw up or have a change. When you spend a lot of money on an unchangeable ticket you’re playing with fire. The AAgent probably neglected to tell him that he would forfeit the whole itinerary if he skipped the first part and I can see how that could happen but I don’t believe the AAgent was trying to screw him over.