Check out this article under:
15. What if the airline denies me boarding because I dont have the right ducuments?
https://www.elliott.org/ultimate-con...s-me-boarding/
It seems if an airline thinks the documents are invalid but are mistaken all they need to do is provide alternate flight in a timely manner.
So if my wife's original flight was oversold AA would have benefited by claiming a document issue rather than overselling requiring compensation. Makes you think. Can they prove there was a document issue. This was the return legs and there were zero issues going out. I guess they do not have to.