And likewise from a moral perspective: Minsky did harm her. Regardless of his knowledge of the situation at the time, I would expect him (were he still alive) to apologize and do whatever he could to try and heal the pain he caused.
However, I do also think it would reflect much differently on his character if he knew all the details of the situation he was in vs. if he did not. That, from what I've seen, is still unclear.
Consequences and intent both matter.
So he did not harm her.
However, if it did, to be fair, you would have to seriously consider if it is reasonable to assume that person was ignorant. For example, if you know your friend is a drug dealer and he asks you to "drop off a bag at another house", you would get the book thrown at you even if you didn't know they were drugs in the bag.
If someone Minsky's age went out and started dating and having sex with high schoolers, he would go to jail. Period. Regardless of the exact social dynamics.
Remember that before making absolute statements about mental powers.
By the way, coerced sex (sometimes rape, sometimes assault, sometimes pimping, in some places prostitution) is illegal among adults too. You can keep it extra illegal for minors.
Minority should not be an absolute but treated as a high bar. (The younger, the higher.)
Unfortunately legislatives are black and white in most countries, and people accede to it.