I've fenced on and off for 20 years, and the worst injury I've seen is bruises, thank goodness. My only concern these days is the blade breaking and sliding under the throat guard.
All three incidents against beginners who were far too enthusiastic, and coming way too hard and way too close.
The other I don't remember precisely, just that it was a tall brute who was just coming at me. Avoided him with cause every time after
I was always fairly invested in not being an asshole so I never back-flicked in a tournament until I was 95% sure I could pull it off (practice on willing accomplices ofc).