How can you be so careless in the first place by trying to test someone without your wallet, which has your holdings in it? If I may ask, if you really want to know if the person is capable of doing whatever they claim to do, why not create a new wallet without any holdings inside and see what the result will be? You will have nothing to lose.

If you said you lost about 0.12 bitcoin to the accused guy, which means your wallet might be the same wallet the user said, just moved the funds he found there to an exchange.  
 
I can't just draw my conclusion around this; it's either you are the same person operating both accounts and claiming you have been robbed just to try to make a point that you know how to access someone's wallet,
 
Or you were just careless enough to play into the hands of someone who will be spending your money in a bear parlour or a gambling hall right now.