Scary reminder that this sport can be risky.
I was recently on a long pull-through trip with my friend when, standing on a ledge over the last pitch, they clipped their karabiner into the loop and rigged their descender on the wrong side.
They then swung out as usual only they had just thrown themselves down a pitch. I saw them fall back and bounce headfirst off a rock before landing on a lower ledge. They were all physically okay but had it been any of the previous pitches, they would've died.
It was just very scary to watch. I've since had a nightmare about falling off a pitch. This sport mostly feels safe, but this has been a brutal reminder of the fact that it only takes two consecutive mistakes and it's all over.
Suddenly the lectures from my elder cavers about having my kit be perfect and doing everything totally right is less picky and more appreciated.
Edit: they swung out to test their descender because they clipped their cowstails into the knot. They were trying to test their descender when they fell. The wrong rope was going straight into a bag.