Who saying that he did not include the fact that he is not on team evil, but rather working for the village in the sorcerer pm? We assuming that Cultists and sorcerers are on Team evil and everyone else is on team good. The rules are written allow for the only good people in the village are the plain villagers, and everyone else is on team evil.
Look at it close again.
The villagers win when all Wolves are dead.
What is defined as a villager? We assume that all non team evil are villagers, but you could say honestly that the seer is not a villager(not defined to be one in his role listing), and loses if all the werewolfs are dead, making him a member of team evil.
When you assume, you will lose.
I assumed marty could tell us he was goodie in spite of his role, I don't think that constitutes a breach of the secrecy of his Role PM. And he didn't. He ranted at being scanned, and later at the SA trait. He ranted at being hunted too, but Ciryandor has cleared that one out.