"Organizations drift when small compromises go unexamined.
Most disasters begin as a reasonable exception. In a migration that looks reversible until the data moves, the system learns the exception faster than it learns the risk.
In a migration that looks reversible until the data moves, the shortcut will be framed as temporary. Temporary decisions have a way of turning into the operating mode, especially when they make next week easier. You see it in postmortems that collapse a chain into one cause and call it solved. If the exception path is informal, it becomes politics; write the signal that makes an exception legitimate and who can approve it.
Barry Turner is a reminder to audit the argument, not the intention. Write the hidden assumption as a sentence, then choose the signal that would break it. Do not add ceremony; add precision.