I feel like this buries the lede massively: Qantas' system was run by Amadeus, who also run the booking system for some 200 other airlines [0]. If you could do this with Qantas and get all those notes, you could probably do it to any other airline and get them too. That would be bad enough, but it also appears that this issue (or one very much like it) has been reported widely at least back in early 2019. So, either…
Some airlines just use a single "god mode" account for their whole e-commerce platform because it's cheaper / more convenient for their developers / vendors.