> IMHO the only questionable pilot decision here is to divert to Edinburgh rather than Manchester immediately. But this is somewhat understandable: first of all, dropping the passengers off at Edinburgh (an hour drive from Glasgow) is significantly less costly and less inconvenient than dropping them at Manchester (an overnight bus ride).

Yeah, as someone who knows next to nothing about airlines, but has seen these type of decisions in businesses, this was the thing that stood out to me. This is all pure speculation of course, but I'd be curious how clear it was that Edinburgh would also have a high risk of being unsuccessful and whether the pilots felt any pressure to try that anyway. E.g. are there consequences for pilots who cause delays for passengers?