In my experience any changeset that has the tag source=knowledge is usually wrong 
.
This one does look problematic for a number of reasons (both what should be in each relation, and how each relation was previously represented in OSM). This does not mean that the previous state was 100% correct, so I’d be interested to hear whether people think we ought to “revert and discuss” or “fix forward”. Personally I’d lean toward the former, but it’d be interesting to see what other people think.
We probably need to decide soon to make any potential revert easier.
(for completeness see also here)
I’m for “revert and discuss”. There are a lot of data users who rely on the state of international boundaries. Such significant changes to international boundaries should never be done without prior discussion. This changeset also leaves all the Overseas Territories in a state were they are in two overlapping admin_level=2 areas.
My understanding is that while the British Overseas Territories are (to varying degrees) administered and controlled by the UK Government and have the King as head of State, they are not formally part of the UK itself.
Regardless of the merits of any change though, I agree with @lonvia that the changeset should be reverted straight away, while we discuss if there’s any reason to adjust the OSM representation that existed until then.
Reverted. On the changeset I’ve suggested that they join the discussion here.
Both relations validate OK in JOSM afterwards. One intermediate revision was lost, but it looks like that was trying to address issues in the previous change.
Oh hey, it’s the same guy that created multiple duplicate United Kingdom relations in the Carribbean just 2 months ago (Changeset: 178965700 | OpenStreetMap). Revert with prejudice. I’ve already cleaned up loads of broken and questionable changesets.
I support the revert and discussion before any future edits.
This user changed Derry/Londonderry to just “Londonderry” without consulting either the Irish or GB communities (and claimed that someone happened to be using his account)
There seems to be a bit of a theme going on here.
Note that any EEZs of British Overseas Territories are legally separate from the “UK’s EEZ” which is defined in the Exclusive Economic Zone Order 2013, which is referenced as the related_law on the EEZ relation:
Article 2 of [the Exclusive Economic Zone Order 2013] declares the area of the United Kingdom’s exclusive economic zone. It reflects the treaties which have been concluded with the Belgium, Denmark, France, Ireland, the Netherlands and Norway, and the understanding with Germany. […]