Case of some dude with niche interests who only knows of "Lolita" from the Japanese cultural perspective, which is more focused on a specific fashion style and has no direct relation to the book.
Honestly, he wasn't doing anything wrong. From the picture in the article, all he would do is wear frilly dresses; probably thought the students would find it amusing. Like... Big deal? Not like he was diddling the kids or anything. People need to stop being so judgemental.