"John, so you think Atillo should give the domain back to domainp and wash his hands of this matter? As easy as that sounds, it just doesn't seem like the right move to me."
It depends on what you mean by "right". There are things that one can do which minimize one's potential legal exposure. There are things that one can do which resonate with one's personal morals... There is a whole world of "right" things to do - they do not always point in the same direction.
There are facts in dispute here, and resolving them on the basis of whatever possibly forged, possibly not, documentation is provided to Attillio and letting him be judge and jury is not the right answer. Someone earlier said "stolen property goes back to its original owner". Well, it doesn't do that on its own, and adding a possibly flawed judgment by a genuinely well-meaning person does not guarantee the "right" result (according to one's definition of right). If appropriate authorities can order it transferred from Attillio to someone who "should" have it, then they can do the same thing no matter where the domain ends up after Atillio gives it back to the person he did not pay for the domain.
I did not say that Atillio stole the domain. However, amidst the competing assertions here, we know that Atillio obtained the domain on his basis of a promise to pay $3,000 in exchange for that domain. We also know that Atillio did not pay the $3,000 he promised to pay for the domain name. Now, please hear me, he may well have sound moral reasons for wanting not to carry out his promise. However, what we agree upon is that he did not carry out his promise, and he has kept control of the domain name. I have no quarrel with a moral argument that says he is doing the "right" thing there. But you have to understand that one is making a moral choice in breaking one promise because one believes there is a reason to break that promise.
Sentimentally, I agree that domainp's story does not fit together well, and it is clear that when he told opencg he could transfer it right now that domainp knew he did not have the power to do so. That tells us that domainp has a capacity for saying things that are not true. I am also confused by the apparent situation of offering a domain name on eBay while at the same time offering it for bids elsewhere. That is not how one conducts an auction, but I may have the chronology confused a bit.
None of my reservations about domainp's candor changes the fact that Atillio promised to pay $3,000 for a domain name, and has obtained the domain name without following through on his promise. I agree that one thing he might do is to simply maintain the status quo until the dust settles and an appropriate authority makes a determination. I disagree that he should appoint himself as that authority - an error in judgment on his part renders him liable, whereas following the order of a competent authority does not. Either way, there does not seem to be tremendous urgency here.
And absolutely nothing would change my view that a payment of $3,000 from opencg to domainp has the effect of obligating Atillio to transfer the domain name to opencg. If domainp had accepted an offer to sell the domain name to opencg prior to accepting Atillio's offer, then why on earth did domainp transfer the domain name to Atillio?
Back on the subject of "right" here, there is one party which clearly admits having failed to comply with the terms of a contract, and that is, unfortunately, Atillio. While Atillio may have a defense of illegality or some other intervening cause for not performing the contract, I do not see how an allegation that domainp stole the domain name entitles Atillio to maintain possession of it. As we all agree, the one person who is known NOT to have paid anything for the domain name is Atillio - and it is an odd fact that he is the one who happens to have it at the moment.
So, yes, I perfectly understand Atillio's inclination not to do anything at the moment. But the idea that the domain name should belong to the one guy who admits not having paid for it should at least cause some cognitive dissonance in the minds of those who see things with apparent moral clarity.