Actually, he didn't find it with a boroscope.
He stated his "mechanic" said
it was good to go, then it wasn't after ball honing.
The only time a boroscope came into play was when he inspected it the day he bought it.
Again how does he say it's okay, then all the sudden it's not? After a hone, mind you?
The OP got ripped alright. He should be looking at his mechanic friend as to where the ripping came from.