Harry, I just stumbled across a piece of information that might be relevant here. You may already know this, but who knows?
In the NBA thrad (off-topic forum) Orevin says he supports the Mavs because he is German:
Being german, I'm kind of a fan of the Mavs. However, my sympathy is shifting dramatically towards the Warriors. I never saw them playing during the regular season, my loss! They are so much fun to watch, just like the Suns! Well, then there are the Bulls. Impressive how the beat the Heat... I will definitely go to at least on game when they host the Pistons. Will be my first NBA basketball game I watch live in an Arena!
Now, from my experience, many Americans claim to be German, Italian, Irish, Chinese etc., referring to their heritage rather than their country of citizenship.
However, there is one interesting feature in Orevin's posting: he talks about his
sympathy. It went unnoticed, but there is something strange about the sentence: if you root for a team there is usually no sympathy that can shift (except you are from Portland and a Blazers fan

).
Now, here it gets interesting: There is a German word "Sympathie" which DOES NOT translate to English "sympathy" but rather to something like "favor, love, affection" etc. Although these are also possible meaning of "sympathy," Americans rarely use the word in that sense (they usually mean "pity" etc.).
Many, many Germans speaking English use sympathy the way Orevin does, which leads me to the assumption that Orevin is indeed a German citizen. While I feel ashamed that a fellow German behaves so dishonestly, this might be a good thing. Chances are that Orevin was an international student or even an exchange student who thought he might make some easy money before leaving the U.S.
This is pure speculation, of course. But if you have Orevin's real name, you might want to check German Google and databases. It is almost impossible being German and not having some information about you on the net.
You might even want to talk to the Chicago authorities and point them to the major Chicago universities to see if they have the name in their registers.