Neither: I'm saying that because it was the way it was resolved in the case that went to Court in Germany and which led to airlines having to allow people to fly non sequentially from there (though I didn't realise KL included that from all countries, not just Germany but I don't really see why they should do it differently, especially if it means surrendering something that benefits them for no reason).

PS: Sorry to hagi but I think it is quite absurd to claim that the video is "proof" that one can fly out of sequence without fare recalculation. The video is about some pretty arrogant blogger gloating about a fare mistake ("super discounted"??) of $500 for CDG-SFO in P that he ended up being able to fly, He had an issue with being incorrectly denied boarding as the passenger wanted to transit without visa in Algeria, and AF had cancelled the ALG-CDG flight multiple times, etc. He arrived at CDG and the fare was identified as a mistake and he was downgraded to Y but his PA called again to get the AF call centre to honour the mistake fare and for whatever reason, they ended up giving in. It may be a case of someone at the airline showing mercy when a passenger had their travel plans disrupted multiple times, more likely of an airline deciding that it didn't want to upset some big travel blogger (they give many bloggers free tickets anyway) or whatever. For the record, in the story, the €1500 fee theory and how it works is not even tested. It is attempted, the discussion moves immediately to the question of the mistake fare and a downgrade to Y, and the resolution is that someone the assistant calls at AF ends up reinstating a P seat. But the video neither proves that there will be no fare recalculation when routing changes, nor that fare mistakes will be honoured. It just proves that luck exists and great for him.