You came up with a logical plan, based on your current knowledge. Interviewer tried to make you dit about and change your plan, but you stuck to known information and logic. If you'd started to feel sorry for the Jumbo pilot 'cos he was tired, you would start to doubt your plan, and dig yourself a big hole [trust me, the interviewer would have lent you a spade]. You didn't so don't sweat it.
Of course, the jumbo was paying your wages. The two trainers would just about buy a jar of coffee for the company. We try not to kill the golden-egg laying domestic fowl when at all possible.
Oh and "fuel emergency" = queue jumper. You want a priority service, you have to declare an emergency. This entails Mr Pilot having to fill in a lot of boring paperwork. Mr Pilot doesn't like paperwork.