A similar phenomenon is found with the term משמיה ד׳ which means the same thing and has the same connotation: an indirect quote of a rabbi who is usually two generations later than the one with whom the quote was to have originated. This is in apposition to a rabbi directly quoting one of his teachers (e.g. Rav Yehudah quoting Rav).*
My little rant is that people who translate Talmudic passages are not usually attuned to such differences and I get frustrated when direct citations are turned into indirect citations. Not everything is "in the name of" a rabbi, sometimes that rabbi heard it, himself, from the first rabbi.
* I had a conversation with Professor Yaakov Elman on 14 June 2007, where he confirmed my suspicion regarding the matter and pointed me to look to Yevamos 18b for a stammaitic conversation regarding this issue.