What was the knot?
Be careful with this one.
When used on friends, use something soft and about 3/8” diameter so it does not cut.
For others, a long shoelace works well, back it up with a couple of half hitches.
Have a stout bandage shears ready.
https://en.m.wikipedia.org/wiki/Constrictor_knot
Thanks! I was familiar with it. Nasty thing.
I’m always looking for knots that will hold reliably and untie easily (boating).