The motivation, potentially, is to fish for information. Pedescribe may have accidentally revealed a power, or he may have been commenting on the flavor. There’s no reason for Pleo to know which.
Masons are more powerful late game than early game. That’s why you don’t want them revealed early. And having masons decide the lynch is a terrible idea, as it removes all burden from the scum to post opinions and make cases. If they aren’t taking stands, how the hell do you expect to find them?
Here’s the thing. If you’re looking at two potential actions, where one has a clear townie motivation and one has a clear scum motivation, then it makes no sense to claim “well, he did the townie thing, and scum woud never do that.” Because, of course, doing the townie-er thing is reason enough. We’re in agreement up to here.
So where does it make sense to say “scum would never do that”? When the decision is between inaction, and taking an action that draws attention. If a suspect takes an action that doesn’t benefit scum, and had the option to simply doing nothing (and no one would be the wiser), then I tend to consider that a strong indicator of townieness.
Could scum manipulate that to try and clear themselves? Potentially, but it’s an incredibly risky play. Most people don’t view that the way I do, so it’s not going to clear them in very many eyes. It runs the very large risk of going the way my gambit in the last game did, and simply getting them lynched. IOW, such a play has medium reward, but very high risk. And, of course, even getting to that point requires perfect play. Any slip at all in the sequence of events, or tipping your hand that you wanted people to see the event, totally nullifies it. And given that you’d be under scrutiny, it’s tough to actually play that perfectly.