It doesn’t take much to have to reject and scrap a bunch of cast parts if you aren’t doing constant dimensional checks on CTQ’s. Lucky for them they caught the issue before all the machining time was wasted. I had to deal with crap like this from vendors for years. Hurts the supplier, hurts the manufacturer, and hurts customers when their product can’t be shipped for weeks or months because the order has to get back in the casting rotation.