Patients are still blinded - exactly when they find out which group they were in is an interesting question though - I have no idea about the timing - theoretically, they could be told after the data lock (I think), certainly could be told after initial results are released, but in reality when they're informed is unknown.
Per "will they start feeling like crap when they go off V", that's interesting as well - depends on whether they have creaky old muscles and joints like some of us here, and noticed improvements in pain levels after entering the trial. But the real question is "how long does it take for the anti-inflammatory effects of high dose EPA to wear off?" - for many of us, it took weeks to months to see a be difference, perhaps as EPA levels built up and chronic inflammation slowly subsided - I sorta doubt you'd go right back to being in pain shortly after stopping V, would take time for the inflammation to build up to original levels. Would be an interesting experiment to run, but I ain't gonna volunteer to be the guinea pig!