That's addressed in the article.
The fact you say "The article" makes me wonder if you read either. There are two...
The thing is, I read both articles. Neither of them address the position of power issue. One says "she felt trapped". But how? That makes NO SENSE when you can so easily block or otherwise ignore people communicating solely over social media, which offer many means for blocking annoying people. There is no means of trapping someone.
I would understand how someone might "feel trapped" if they were a student attending a college into which they had put forward substantial tuition. I would understand if they were to gain credit from a course needed to move forward in education. Even just being in physical proximity I could see it. There are a lot of circumstances in which I can image someone feeling trapped in some way, where there was a small amount of power to leverage - but not in this case. The course was free, the grades if any counted for nothing. The moment the contact started getting lewd the person should have broke off contact, and could easily have done so.
I'll leave the RRTFA to the person willing to make an argument/ask a question that takes the entire article into account, as you have utterly failed to do.