Terrible example by me, sure. But do you know of any Middle Eastern revolutions supported by AIM? Long form journalism ala @MayorEmanuel? Any academic studies examining mood on AIM and how it correlates to stock market performance?
If the reason your not offering someone a job is because they messed up technical questions, I think its a good idea to give them candid feedback on the spot. Its objective. If you are having to choose among several qualified candidates, then I think this is asking for trouble, since there isnt an objective clear reason for the person not getting the job.