While you're correct, you're not pedantic enough. Using X-rays to validate the most critical engine parts has been done for literally years and is a relatively boring and old part of "rocket science". Don't expect SpaceX to spend some serious cash on this and techniques such as this (MRI and sonic / ultrasound tech comes to mind).

Source: a good friend of mine is a structural engineer for Aerospace Corporation (a rocket scientist if you will) and I'm an avid r/SpaceX reader.