A perp signature in comments is equivocation. And the equivocation is usually symmetrical suggesting a formula is being followed. The first half of the comment will propose one point of view. But the second half of the comment will propose the opposite. It is hard to argue with a person who does this. If you challenge one part of what they have said they will say you misunderstood them and fall back on the other side of the argument. You cannot pin them down.
A genuine person is trying to get their viewpoint across. They might ramble a bit but it will be clear what they are trying to say.
The Professional Liars feel most comfortable never expressing a viewpoint that they have to stick with.