At most, that's just a technicality. Obama did go to his services for 20 years. Did he sleep though the sermons then? There is no way but to be brain dead that he couldn't know what Wright stood for. Then to be there for twenty years!
I'm pretty sure i heard an audio clip of Obama using that phrase on talk radio. You are right though. The term has been burned into our minds, and may be factually in error. In a simple search, I was unable to find such a transcript. Maybe it was in a book? Regardless, I think Obama used the phrase, but yes. I could be wrong.