What broke
A session opened on a branch with no journal entry, so entry fell back to an older entry whose next action read "authorise phase 3", while HEAD was the merge commit that delivered phase 3. The entry had not been superseded; it had been completed, by a session whose own entry was still sitting in an open pull request.
The rule it paid for
Precedence orders sources, not claims. A next action that observed Git already falsifies is not current, whatever its rank, and the entry that won says so.