Of course - but again, the law doesn't specify that a "competent person" has to be on that list, or any list.

There was a huge debate about this couple years ago, when someone asked "can a foreign electrician certify a UK electrical installation as safe", and after very long debate the outcome was that yes, they can, because the British regulations never actually specify what they mean by "competent" and a certified electrician(even if foreign) is definitely "competent" even if not registered with any UK based authority.