You're right, Shuji. "Lesson" really shouldn't be used as a verb, and if it were, it would probably mean to give a lesson, not to receive one. Keep in mind that students simply go to confirm a lesson and suddenly find they're supposed to leave a review, so they may write one hastily. Your student may have mixed up two thoughts in his head. I've made mistakes myself. Unfortunately, there's no way to edit the reviews. (Although if it's something serious, you could try contacting support.)