Isn't that just another kind of trick question? It seems like that relies a lot on the interviewee guessing that you aren't looking for a standard complex solution.

By "trick question", people usually mean the questions that won't occur in real job. This does not seem the case here.

I have no idea what the OP's actual questions was, but as a made-up example: If the problem is solvable with static sqlite database copied to every node during deployment, but candidate suggests master-master postgres cluster instead, I would not want them. I shudder just thinking what kind of monstrosity they'd build if hired.