If you mean the weapon was prone to fire when the bolt was closed, I heard that.
I also read of cases where the thing went off if you bumped it (safety ON).
I have a couple, and even more so than my other weapons, I handle them both as if they were loaded, safety off, always.
My bet would be that in this case someone’s finger got in the trigger guard as the gun was being handed off. Purely an educated guess.