I had an interesting one once by a certain Irish budget carrier. This is what he asked me and these are my answers:
Capt: Its Xmas eve, you have 189 Pax on board and you need to get back, you find a nav light is not working. What do you do?
Me: Check the MEL to see if its needed.
Capt: The MEL requires you to have it working.
Me: Tell the engineers.
Capt:Theyve all gone home its late at night.
Me: See if I can fix it myself (I know its a stupid one but I got pushed into a corner)
Capt: You dont have a ladder. Your Capt has to get back to EMA hes asking you if your going to stay or go with him.
Me: Id go but i would strongly object to it.
With hindsight I should have said to him that I would not go but I was confused because the airline in question is known to bend rules, so I didnt know if they wanted to see if I would do it.
What do you think I should have said?
Would have to check the MEL but can the flight be completed during daylight hours? It may be Christmas Eve but it may still be daylight!
Or call the company and ask whether a dispensation can be issued for this particular flight.
However I must take issue with your comment "..because the airline in question is known to bend the rules...". I am not sure which company you are talking about but if it's who I think then I can assure you that they do NOT expect their crews to bend the rules! Any potential employer expects their employees to obey the rules and I think you are making a very wrong assumption here and indeed if you want to be successful at future interviews (with any company) then I suggest you change your tack.
But of course it's not just a question of rigidly following a set of rules. As I have suggested above, ask yourself the question "Is there any way I can despatch WITHIN the rules?"
A/c operation and crew coordination isn't just a question of doing "things right" but doing the "right thing" - they are not the same.
Good luck in any future interviews.