Originally Posted by
Often1
There is no precedential authority that a carrier must rebook OA. Some do and some don't. Some rebook high-level elites OA and others do not. But, EC 261/2004 does not require OA rebooking, at least now.
There is also nothing in the Regulation which suggests that if one uses self-help to rebook, that one may simply claim it back from the operating carrier.
The key is to be forewarned that one may well eat the cost of the self-help.
That's why I wrote that "It is unclear what "under comparable transport conditions" means." It may well be that the conditions are not comparable if the carrier is not the same as the one originally booked.
If the carrier doesn't fulfill its rebooking obligations, the passenger would normally be entitled to compensations. Ideally, the obligations should be tested in court so that people will know what rights they have. However, it could be expensive for the passenger to test this if the passenger is wrong, so it's better if it is tested by "someone else" who would then be the one who risks having to pay a large amount of money.