There are a few possibilitiea:
- insane cop (gets opposite result, usually doesn't know about that)
- busdriver targeted me and mafia, changing our places and Pero visited mafia in fact but he doesn't know
- mafia has an ability to change cop's result
Etc
Or
- he lies, but is hard to consider mafia would trade 1:1 with a player who can be mislynched because I defended scum very strong, so my take is that he doesn't lie, he only spread the lie he received