OUCH! Big ouch!
I know that story very well from my own experience.
About 40 years ago I did that with a residential roll up awning. Didn't pin it, thought I could hold it.... stub arm rotated and unloaded on the knuckles of my left hand. Severely beat my hand about a dozen blows in the time it took me to react and pull my hand out of the way.
Thanks for the reminder! Yes, those springs can literally kill you if you're not careful.
I was lucky, nothing broken but I sure was bruised and sore for a very long time.
40 plus years later I am still very leary of anything with a big spring in it, especially garage doors.
