So the gate staff will have been checking/scanning for DUS, but the crew planning for EDI ��*♀️
Interesting point. Consequences of a domestic or CTA arrival at an international destination might have been interesting if they had disembarked as not all would likely have had passports.
I was a passenger recently on a flight that returned to LHR following loss of a hydraulic system. Right turn East reaching Dover rather than continuing ahead to the Belgian coast after about 20 minutes. Capt gave a PA explaining there was a technical issue which he would prefer to return to base with (contaminated destination runway) and C/C prepared cabin for arrival having just wheeled out the carts to commence food service. It became apparent that a number of my fellow passengers didn't realise we turned back until we touched down at LHR judging by the comments I could hear once they'd removed their personal headphones.