Presumably a medical answer to that. For whatever reason, they considered Athens offered something that Istanbul didn’t. In the days before Medlink, I once had a passenger who was in extremis, and the advice from the RFDS was to take them to Adelaide, even though Darwin was far closer. Basically, if they’d survived getting to Darwin, the RFDS would have had to fly them to Adelaide immediately, as the treatment they needed didn’t exist in NT, and they were already on a much faster aircraft that was already pointed roughly south.
Once the aircraft diverted, it would have become subject to Eurocontrol slots, so a delay getting airborne again is guaranteed. I went to Amsterdam one morning, and after getting fuel, when we asked for a clearance we were told that the next slot wasn’t until around 6 hours away. We had nowhere near enough duty hours available for that, so following the advice of some very helpful ATCs, we started anyway, and got a clearance to taxi to a spot out of the way, but near, the duty runway. The hope was that someone else would miss their slot to London, and that we’d be in a position to grab it. And as luck would have it, we didn’t even have to stop on our taxi out.
