I think this makes sense, but then what’s the learning - dont make bad welds? I imagine they were already trying to do as best they could. Or perhaps “however stringent you think your checks are, they need to be more stringent”. And then learning that repeatedly is somewhat spectacular.

> trying to do as best they could

There's another comment that it wasn't the weld but even if it was the welders would build to spec and "better" (if it's known what better is) only if it's straightforward. There are certainly scenarios where a fabricator could design a better jig or use a more precise process but if the spec doesn't call for it then it's probably not going to happen because there are also the dimensions of time and money that matter as well.