If you honestly can say that you never got on it and pushed the motor, then it was the machinist's fault.
Being a former engine builder, I can tell you how to handle this.
Dont say anything more to this guy. Be nice. Go pick up your engine. Take it to a pro who can identify what happened and why. Get the analysis on paper, and fax it to the moron engine builder. If it turns out it was his fault, then threaten to tie him up in court if he doesnt refund the cost of all the damaged components, and the cost of his labor.
How long has this shop been in business?
Who at the shop did the machining on the block?
What type of equipment does he use? is the equipment all old and beat up? Are the floors all greasy and is there grinding dust settled all over everything? Do they assemble the motors in a clean room?
Did they do a square deck on the block? Sometimes a machinist will goof up and not tell his boss. By the time the **** hits the fan, its too late. If they went to a zero deck, the rods could have stretched, and the pistons would have smacked the heads. Then the mains would have tacoed. Does it look like the pistons hit?
By the way, those main specs are not only all over the place, but they are way off. Every main should be within a couple tenths of one another, and not be out of round by more than .0005