Right, more problems with Audit, in addition to problems mentioned previously. Although Updates to Documents have version numbers, updates to ListItems do not:
Interestingly, Deletes still have a version number. But there really is no version number recorded for updates…
… even when there is Versioning on the list:
In the VersionNo paramater, the Major version is (VersionNo DIV 512) and the Minor version is (VersionNo MOD 512) – thanks to Dink for the hint on that part!