In this case, I would agree with you - this is probably shaping up to be more than just a bugfix release.

If we want to adopt a general policy of always bumping the middle version number, then I think we also have to be explicit with always cutting bugfix releases off the last release tag rather than master. That way, we don't get any decreasing version numbers.

Given our past releases, that could be a bit heavy-handed, but I'm mostly ambivalent.