Well, if the candidate passes, it should be "in command" but if they fail, it could well be dual, depending on what the fail was about.
An ATO must not allow an inadvertent breach of CTA or a dangerous situation to develop. If these are prevented by the ATO, the flight is dual.
In the end, I guess it doesn't really matter. You logging dual is pretty normal. I say you are not really totally in command on a test. You are being told where to go and when to divert. If you were PIC you could say no.