A true story from 40 years ago...
I needed to cut down a tree.
I was worried, because it was pretty close to the house,
so I went up in the tree about 10 feet and chained it tightly
to a nearby tree that was further away from the house
figuring in my mind that would prevent it from falling towards the house.
My theory was correct ...but... (this is a big but)
when I cut through the tree, and when it fell,
the chained portion became a pivot point,
and the butt end flew straight up in the air
temporarily knocking me unconscious and
sending a running chain saw flying through the air.
I came to with my wife standing by me thinking I was dead.
When she found out I was not dead,
she began to berate me for scaring her like that.
You might have to draw a diagram of this to see what went wrong.
I hope your saw had a chain break back then...