Legally, yes. However, if I had children, one of them an adopted daughter, and I "moved in with" a man who professed to love me and who later decided he loved my adopted daughter more, despite the fact that he was 20+ years older than her, I'd feel betrayed and appalled. When a man takes a woman as his "love interest", as Woody did Mia, then seduces her daughter (adopted or not), we are talking about a major betrayal not only to the woman he professed to love, but the child who she adored as a daughter. There is nothing on this planet that can convince me that what Allen did was anything short of an utter betrayal on too many levels to calculate.
I believe the abused and shattered child before I would believe a man who had so brazenly manipulated a minor child and betrayed the woman he professed to "love". The statute of limitations assures that he will never have to answer to the allegations, and because he is a "talented genius", he will never be held to answer for the crimes he has been accused of. People do not want to believe what they do not want to believe. And society will never look too closely, because it does not want to find answers that might reveal its heros have feet of clay.
Even accepting only what Allen has confessed to, he is a perverted swine who seduced and had sex with the adopted daughter of the woman he'd proclaimed to have loved. There is absolutely no going back from that. Ever.