I figured out a way to make this happen consistently, and it seems to be a problem of Gmod itself. You can see it happen in real time by focusing another window that isn't gmod (while gmod runs in windowed mode) or setting your maximum FPS to a really low value, the jiggle bones will glitch out and eventually delete themselves somehow.

I was testing it in gm_construct by the way, and saw no console messages unless you die and spawn a ragdoll, it will go flying with the error saying: