I think your definition of “harassment” may be outdated, at least from a legal standpoint. Per the Fair Housing Act: “Quid pro quo harassment occurs when a housing provider requires a person to submit to an unwelcome request to engage in sexual conduct as a condition of obtaining or maintaining housing or housing-related services.” It was unwelcome and it was a quid pro quo proposition so the key criteria appear to be in place. I would not go so far as to definitively say it is or isn’t harassment, but the situation certainly begs the question.

Setting legalities aside, is there not an ethical problem with a landlord making a tenant feel insecure in the home she is providing for herself and her child? You yourself called it “indecent”. What do you think justice looks like here? I think I can safely say it is not accusing the author of overreacting or of having ulterior motives.