People can change. It was four years ago and longer. He did not say that he sees her changing, he said he see that she is different now. There's a difference. Why should a past such as hers be big red flags? She's not who she was then. If we were all judged for the stupid things we did when we were young, no one would have a relationship. The past is the past. No one is telling him to ignore his feelings. He says she's the dream girl now, so maybe she truly has changed. Only time will tell. If he cuts her off now because of her past, that would be unfortunate. I could see if someone had been jailed for a federal offense or something along those lines, but not this.