Right, now I finally understand what was wrong with him when he was found. Stupidly I thought he'd gone back in for some reason.
It is never said who is calling Reno, it could be Tseng, but it could easilly have been someone else like Rufus, (or maybe Heidegger, since he has some comand over the Turks, doesn't he).
Elena want's to know who "did Tseng in" which is a term for murdering, there is always a possiblity the translaters didn't realize that though.