I think a lot of the errors with UA/AA/DL involve currency issues and non US taxes.

Some of the complex international itineraries can have 20+ tax codes.

Plus when one of the US3 accidentally sells F/J tickets for $100 it makes the news as thats thousands of dollars less than it should be. AS has some expensive tickets but nothing approaching the TATL/TPAC J/F fares that the US3 have.

As people upthread have said, it's hard to tell with AS if it's a true mistake or just a good deal.

If you get a BF TATL ticket on UA for $250 you know it was a mistake!