I find it crazy that nobody was checking the vertical profile after the FAF by any means, and that this was:
...
3. Not picked up by any form of audit
Audits, unfortunately, ignore quite a bit of the technical minutiae. In almost every audit I've ever had the pleasure to be a part of, when it came to any technical discrepancy, the non-pilot auditor was apt to ignore it as they didn't understand it (most common in my experience). Instead, what they should do is point out everything that could be misunderstood by a layperson.
It becomes especially dangerous when the auditor questions a company representative and the question is answered sufficiently that the auditor feels there is no issue. On more than a couple of occasions, I would have to ask the auditors to put in every question they had into the findings report on the theory that just because I could answer their question, did not mean a line pilot could.
Also, auditors are people too. They are often all looking for the same things, but one can only be so effective cross-referencing manuals all day.