Comment by rrr_oh_man

This is pretty universal in my experience any time you have inspectors/auditors intended to enforce a set of rules. The most common case is that they just miss some rule: they can be hard to properly map from what you're seeing to the rules reliably, so different auditors will miss different things (so you can get a sign off from one and then another highlights an actual contradiction).

The next level is that the rules are kind of vague or unclear and so different auditors will have different interpretation of it. You can try to fight it but ultimately the auditor is who needs to sign off on it. This is also why switching auditors can be a right pain.

Then you get interpretations which are flat out contradicted by the rules. Sometimes this is necessary to make the rules work (there's some blanket rule that's impractical to impossible to apply literally, so the auditors contort some interpretation that's more workable), sometimes it's just incompetence, and when it's wrong enough to matter sometimes it's easier to just go along with it than try to escalate the issue with the auditor.

You can also get situations where the auditor has their own pet rules, which aren't written down anywhere, but they will become much more adversarial if they are not followed (sometimes they'll outright tell you what they are, sometimes it's a guessing game).