To go back to JP's original comments though: what was the right thing for him to do, back in January, when he had these concerns? Should he have said "I am therefore -1 on this inclusion"? Should he have been discussing this on the mailing list rather than the tracker? Should he have kept coming back to the ticket and answering every single message reinforcing his original conclusions? I honestly don't think it's very clear what one is "officially" supposed to do.
To me, it's fairly clear: what the committer needs to get is guidance in any action to take. In most cases, the set of possible actions comes down to three: a) reject-as-is b) commit-as-is c) commit-with-changes (specify changes to make) [d) take no action at this point, until certain preconditions are met]
For d), it is common to request, to the submitter, resubmit-with-changes, then the code needs to be reevaluated when the submitter claims to have implemented the requested changes.
In the specific case, JP didn't propose an action to take, hence it wasn't clear (to me) whom his comment was directed to; I understood it as "the module has these minor flaws, they should be fixed at some point", which means "commit, then change later". This is what happened.