I am not a pro, have been occasionaly cutting for a few years. Was wearing eye protection but nothing else. I am deeply aware of kickback, etc so I am careful.
I have Stihl MS362, it was idling in my right hand, with the left hand I was moving something and the next thing I know as I was turning it caught my loose pants in it and shredded a hole in it. Did not touch me. I am not even sure how it happened.
The point is, you can never let you guard down even when it's just idling. Use the brake feature. It's there for that reason.