Hey,
Do you mean the external moderator or second marker? If it's the second marker who has moved your grade 5% either way I don't really think this is a cause for concern, especially in a a discipline like politics and you are still within the same grade boundary (A / Distinction). In our department, for example, the second marker is encouraged to mover the marks about a bit as it signals to the students that the lecturers actually read their work.