I've just emerged from a court hearing (granted against EZY, not BA, but presumably the principle holds), where I learned something that I had not seen explicitly reported anywhere online - any 'rotation' cases, where the airline has decided not to operate an outbound flight on the basis that it would be unable to operate an inbound flight with the same aircraft/crew, are automatically deemed to be an operational decision made by the airline regardless of what the disruption is due to.

In my case, EZY decided to overnight delay my LGW-MXP flight because a slot restriction at LGW meant that the crew would exceed their duty hours and be unable to operate the MXP-LGW sector they had planned for later that evening. Despite the slot restriction, the court found that the delay was caused by the airline and did not amount to extraordinary circumstances.

This was a very satisfying end to a claim that has been dragging on since 2022, including a total of three court hearings including one where the judge essentially told counsel for EZY to settle it and got rather irate when they didn't want to!