nope, they asked the clarifying question, and got the response that there are no business requirements: "That is part of the assessment itself, see what kind of extra features you can come up if any."

They were failed because they could not deal with the answer, they were not failed for act of asking the question itself.

Actually happens sometimes in my work... Q: "Are there any requirements on the database used?" A: "Nope, just make sure the final system will be able to handle the required load"