It's essentially the same as when you were 'confirming' people to be vanilla townies when they used the term 'villager' in Game 2. You may recall, I was not a villager - I was a Yellow Ajah Aes Sedai - and yet through reading the opening post and your discussion with... why was it, CarnCarn? I deduced that was the keyword you were using and used it myself deliberately to demonstrate how the techniques was unfounded.

In this case, it is quite easily deduced from the opening post, and we (or I, anyway) don't even know what the Shadow roles' message contains - if it says, say 'you are against the Tower', it's quite easy to say what you just did. Nor does knowing this actually confirm anything. My role certainly did not contain the words 'You are for the Tower' or anything like it, though it is easily understood to be that way from the text.