When you mine at a pool there is a certain level on anonymity to be expected, but there is also a set of guidelines that your are supposed to follow. It may not be explicitly stated but blatantly stealing (and this guy knows he is stealing) is not commiserate with the ideals of the Bitcoin community. I don't recall signing a huge legal form when applying to BTCGuild but perhaps it may be warranted for all guild operators to make their miners sign forms.
Nobody makes you mine on a pool. It's your choice. The behavior exemplified above is exactly the kind of person the Bitcoin community does not need. It's not some cultural or ethnic bias that we may have - I don't see how anyone can justify that behavior as being proper. If you rat that person out then he/she has no chance in hell of scamming or stealing from somebody else.
It's not like the person is selling marijuana which may or may not agree with an individuals viewpoint/cultural bias. The person is blatantly and willfully violating the trust of Bitcoin network and for that he/she should be reprimanded.
The guy was a jerk, but I disagree with your logic. If anonymity is off the table, and
if miners are called thieves when the pool operator makes mistake, why would anyone mine there? The pool manager then becomes judge, jury, and executioner. What if someone murders the "thief" based on personal contact info revealed? What if someone robs him of 10x more coins than he got? What's "fair"?
Whether he pays the coin back is mostly a moral issue, as they were given to him, not stolen. Ultimately it was the responsibility of the pool to manage the coins.
The pool operator did make a mistake and admitted to it. He did not openly call all those who received overpayment thieves but he did state they probably knew what they were doing. The fact that the operator contacted said person and politely asked for the funds is the correct thing to do is it not?
The fact that the alleged thief laughed in his face is not the correct thing to do is it not? The operator did not enforce any action on this individual. If you know eleuthria then you would know he is a very stand-up guy - the kind that refunds fees when somebody pays too much by making a simple mistake. It is for the bitcoin community to make a judgement as to what to do.
As for your what ifs... well if somebody feels a need to murder another individual over 47 Bitcoin then we have a real problem with our community do we not? Its not like I or eleuthria said to go pummel the guy's head with a baseball bat. I am owed hundreds of thousands of dollars by many patients and I have never sent one to collections because although I would be legally justified to collect payment for my services people would see it as avarice greed. Nor have I used guidos to collect payment...
Releasing the info will simply alert people to avoid dealing with the said individual. Again if some newbie doesn't due his due diligence he would conned from this crook, but I don't think the members of this forums should be subject to having to deal with such people.
Where is the logic failure here?