I used to work in a pressure vessel fabrication shop (for customers like Shell and Exxon). We had a few handheld mass spectrometers for exactly this purpose. Destructive testing was achieved with what we called a "coupon", a piece of metal that ostensibly went through every treatment the base part did. The coupon was destructively tested, then etched and examined with a metallurgical microscope. This level of inspection is achieved by every ASME BPVC VIII compliant fab shop in the US and Canada; many of which are very, very small.
Boeing is outright negligent here if they didn't qualify their parts.