Actually, devil's advocacy is probably the best way to prevent group think (outside of earnest dissent). So well done.

It also occurs to me that some people holding a belief as a result of group think is entirely consistent with the belief being true and even justified-- which is an interesting feature that isn't always be obvious. I think I represent a partial data point against group think in this case because I have a something of a revulsion against the aesthetics of cryonics, some of the social implications and some of the arrogance I see in it's promotion but nonetheless conclude that it is probably a worthwhile gamble.