I would say that what the POWs were saying on TV was sign enough of them having been, well, coerced. I can't imagine the flower of the Royal fleet, and don't get me wrong, I have great admiration for those individuals' keeping it out of the shootin' war stage, so I mean that as a true compliment - I'd be proud as all getout of them if they were mine - anyway, I just can't see them saying those things willingly.
Anyone checked for eyeblink frequency, or is that too old-school? Aren't there prearranged signals for I'm OK/I'm not OK, anyway? I would assume the brass knows full well how they are being treated.