I'm not sure a staging environment would have caught it.

I often find Claude makes changes that _look_ reasonable, but it's only when I really dig in (e.g. when refactoring) that I realise there's insidious problems.

I can imagine the author making the changes in a staging environment, seeing that it _appears_ to be ok, then blowing up production anyway.

(AI aside, staging is a lie: https://www.tomwphillips.co.uk/2026/01/staging-is-a-wasteful...).