I always play correctly for my affiliation (not meta, just a response to my mysterious amount of minus karma).

If you lynch me exclusively for saying something true, like that there is no way to tell who is mafia in a 3 way LYLO without doc saves/cop reports/other investigative stuff/etc. then you're not good at this game by definition. There is hardly anyone on this website that is actually good at this game.

There are no scumtells or towntells, except to the extent that you actually know a player's playstyle (meta, in other words). But you can find mafia using scumslips on occasion or through counterclaims/power role abilities/etc. You can also use basic probability knowledge to increase the chances of finding mafia, like if a cop claims guilty on a given person before the given person CCs. If someone insists on some particular "scumtell" (or "towntell") on a person, that person is either a non-town role or is not good at the game.

Essentially, a statement is true if and only if each of its presuppositions is true and its assertion, if any, is true. A statement is false if less than all of these conditions is satisfied. There is no other way to determine the truth value of a statement.