Like I said at first, if you search for the thumbs down song it acts like it is going to play it, but instead, it plays something else in that vein. Like when you request a song and it creates a station around that, this would be one of the songs that would play after initially playing the requested song.
Slacker tech support claimed that other stations that would potentially play that song would not have it thumbs downed, though I have been listening since I made this post in January and that song has never returned to my car. Really thought it would be more of an "I don't like this kinda stuff" not a "kill this one song". No matter how many Creedence songs I hit thumbs down on new ones keep coming, yet every song I accidentally thumbs down are gone forever.
-Randy