Excellent judge of character

My partner hates that I have better intuition when it comes to shady people. I called it when it came to letting his friend move in with us, lending money to another friend, and how having his brother stay with us would end badly. The absolute best was the girl who was dating his buddy for years. We had double dated, invited them to our home for dinner, and even let them spend the night. I considered her not a close friend but a friend none the less. One night I came home from work and she over without her boyfriend. No biggie, I total trust him, he'd never hurt me or betray his friend. But something about the situation leads me to go (after she had left) "hey I'd prefer if she weren't here when I'm not home." Suddenly I'm jealous and don't trust him, no I trust you but not her. Fast forward he's going to a friends bday party, later that night he gets home and goes "yeah you were totally right". Apparently she got shit faced and he didn't like how this dude kept following her around feeding her drinks. So he offers to drive her home, they get in the car and she immediately jumps on him. He's pushing her into the passenger seat putting the belt on her telling her no, this isn't ever going to happen. She bursts into tears saying how she's loves him, has loved him for a long time. That she broke up with his friend so she could be with him, how I don't deserve him and she can make him happy. He tells her he is happy, he loves me and he could never see her as anything other than a friend, maybe not even as that anymore. We haven't seen her since. So my question is have you ever had something tell you someone was no good?