I work in a regulated bank and yday night I had to have an auditor look at us deploying a new version on one user, trigger one order, revert back. He ll then spend the next 3 days studying the changes (that we didnt test in front of him) to tell us if yes or not we can deploy.

And god forbid we find a bug in prod, to rollback I suspect we ll need to retrigger an audit :D Next time you ask loudly your representatives to regulate banks even more, think of us poor assholes spending our time filling mindless paperwork :D