Final, you're looking at Rule 6 (b). Rule 5 (3) (b) is headed The 500 feet rule and says 'Except with the written permission of the CAA, an aircraft shall not be flown closer than 500 feet to any person, vessel, vehicle or structure.'
In your scenario, assuming there's nothing pertinent that you're not telling us, I cannot see why any of the exemptions in Rule 6 would apply.
Dunno why, but I like these thought games. Maybe I should have been a lawyer......I'm sure I would have made more money!