I think we are interpreting Malcolm's position very differently. Malcolm isn't saying "I would be surprised; I put a low probability that the British government would do that." Malcolm appears offended- it is impossible because the British are too decent. You are right that one could, say, be less surprised by an American assassination attempt than a Canadian assassination attempt based on past actions of the governments, but that's not what Malcolm is doing here. He's exhibiting a nationalistic, self-serving bias, which Wittgenstein is right to object to.
I am not concerned with whether Malcolm was correct, and I'm not saying that Wittgenstein had nothing to object to. This is not a situation where we're judging them as symmetrical parties in a debate, but a situation where we discuss whether Wittgenstein's position deserves to be pointed out as an outstanding example of rationality. And it seems tome that even if one takes a much less favorable view of Malcolm, Wittgenstein is still displaying a fair amount of mind-killing biases.
Here's the new thread for posting quotes, with the usual rules: