Who is to say it was that specific sarcastic post that COR focused on? That poster has almost 200 other posts on the CRGP board, and many here as well. It might be one of the other 200+ that got COR's attention.
The point about leaving out many important aliases is important. We have to ask why that may be. Either they are dumb as a rock and just missed the blatant promotion by those posters, or they don't think they will yield anything of value by trying to find them (undoubtedly true, as I am sure they didn't use a real name just like they did with Adam Carter), or they are not after the data that information would provide, or they already have that information.
I think it may be a combination of at least 2 of the above. They seem to me to be more interested in the private communications with the real people, which may include PM's, E-mails, off-line chats, and even phone calls. The documentation seems to suggest that COR believes that at least some of the promotion was orchestrated by the people behind the scam with other posters, either willingly or unwittingly. The people that received them would still have those communications, or could get them. The fake aliases behind the scheme would not.