I made a booking on aa.com for a discounted business seat on a BA European flight about a year ago. Having explored some alternatives at some point I went back to the booking page to make the reservation. It was only after I had made the purchase that I noticed that the booking page had reverted to default dates while retaining my other information (I have not seen this happen recently, maybe it is a bug that has been fixed?).
I immediately called AA res who told me they could do nothing as the fare was nor changeable or refundable, and I should call BA. BA told me they could not change it as the reservation was made on AA.
In desperation I called web services to complain about the bug. I don't think they understood my explanation of the bug. Nor did they seem to understand my comment that US format dates are confusing for a European. But they did observe that this was an expensive mistake to make (about $500!). They then volunteered the explanation that the date controls are very small and it is easy to set them wrongly, so they would cancel the ticket and refund me on this occasion.
I was very grateful. This was in my pre-Plat pre-FT days.
I had the impression that the volunteered explanation fitted some acceptable category. And maybe web services had a way of dealing with it that did not lose AA the $500?