I have a friend who is a therapist/coach and running an online coaching group. Recently he has had coaching group alumni volunteer to help with behind the scenes tasks such as moderating discussions via web and video and uploading recordings.   (Coaching groups are 1 hour 3 times a week and  last 10 weeks for his program. Average time commitment for these volunteers is 5-7 hours) 

Is he at any legal risk having volunteers in this capacity? 

My recommendation was to have him create a contract stating they were aware this was an unpaid volunteer position but then I ran across this article that has me second guessing myself. 

https://www.hrdive.com/news/got-volunteers-not-if-youre-a-for-profit-company/506084/