I don't understand how the analogy stands? The warning was if [Brexit/Trump] then bad market outcome because those things are intrinsically bad. It's not a bug that can be fixed - it's a situation to be analysed.

Not only that but the bad impact was one of the given reasons to not do the thing in the first place. "A Brexit vote might cause some problems but they are fixable" is a pretty different message to "A Brexit vote will cause an instant recession".