It can still be blameless though? The 'because' makes it sound like that's a correct reason to leave it; that the only error was thinking they were unused. (i.e

It can still be blameless though? The 'because' makes it sound like that's a correct reason to leave it; that the only error was thinking they were unused. (i.e. that it's fine to leave them if unused, only a problem if they're used) i.e. instead of 'because they were mistakenly thought to be unused' you can say 'because they were mistakenly thought to be ok to leave as unused' (or something less awkward depending on exactly what the scenario was) and there's no more blame there? And if you really want to emphasise blamelessness you can say how your processes and training failed to sufficiently encourage least privilege, etc.