What do you do if you buy a stolen car, let a forum decide who gets it back?
Not on your life, you retain it until the authorities decide where it belongs or they take possession of it as evidence, to pass it on again would be a very foolish thing to do.
If you pass it on you risk someone coming after you whatever you do and facing a lawsuit by some aggrieved buyer, not to mention grief from the authorities. If the authorities decide on ownership then nobody can come after you legitimately.
My suggestion - for the moment setup a "trust" account at Enom and put the domain in that account, if you believe someone to be the genuine owner then set the whois to him and the contact emails (admin etc) to you. Thereby you create an ethical situation in that you are acting in integrity and not claiming to be the owner of the domain but at the same time you are caring for it until some authority decides on true ownership. Email all who are involved and appear to have a claim on the name and tell them exactly what you have done and suggest that they speak with the authorities in their location.
When the authorities decide on ownership or takes control of the name then you are out of the loop.