Neverknew,
Define the difference with your friend between a "prophesy/prediction" and an "expectation". The WT loves to exchange those words as it suits them when they are 2 different things. Second, in the Jan. WT (thanks 00Dad) there was never a prophesy/prediction mentioned in any of those verses they cited. Your buddy will probably cite the same verses. Those were wrong expectations, while the Society has commited false prophesy.
Show him Deut 18:21 where it says even one false prophesy makes them a Biblical false prophet & should be avoided.
Then he'll say, "They weren't prophesies, they were just predictions." Then show him the Aug. 15, 2012(?) WT with the mushroom cloud on the cover where they criticize Harold Camping (the May 21st nut). They call his May 21st balony both a "prediction" & a "prophesy". So a prediction is a prophesy.
I will echo an earlier post. I had a very good friend that I knew long before the WT abducted him. He assured me nothing would ever change between us. He now hates me because I patiently asked him questions he couldn't answer.
God bless you for trying but prepare yourself... stupid cult.