If this saw blade attaches in the same way as demo saw blades do, a single bolt is all that holds it in place.
Perhaps the bolt was overtightened, weakening it and causing it to snap, releasing the saw at a high rpm. I don’t know that undertightening would cause the same issue, because the way the threads run on the saw, the bolt tends to get tighter as the saw spins up.
I am surprised at the speed of the saw blade, they must have been at full power with the saw blade barely in the ground, for it to launch like that.
