Perhaps before your time, Wiz, EK's B777-200ERs were known as B777-200IGWs. They were later re-designated as -200ERs so correct me if I'm wrong but there was never any such thing designed as a B777-200ER. This may be what your friend is referring to.
I suspect you are exactly right. But once it was pointed out to him that the aircraft in question WAS a RR powered 200 ER (in current parlance) there was simply no way he would admit it.