Added 12 minutes later
Even if the clue is wrong... The ratio of possible roles for Haven is 11 to 8. However, I know for sure that my role cannot be his. Nor can any other peaceful role. So the ratio changes to 10 to 8. Then the chance that Haven is Mafia or a Man is 44 percent. That's not that small. So even if you doubt the clue, vote to execute him. With a 44% probability, it will be successful.