Exemptions from the low flying prohibitions
6. The exemptions from the low flying prohibitions are as follows—
This rule, together with "normal aviation practice" and any mention of "licensed aerodromes" in this context, is part of the Rules of the Air Regulations 2007, which were superseded by Part-SERA and the Rules of the Air Regulations 2015 which supplement Part-SERA. The 500 ft rule is in Part-SERA, not RotA2015.
RotA2015 does contain:
Landing and taking off within congested areas and near open-air assemblies
5.—(1) An aircraft must not take off or land within a congested area of any city, town or settlement except—
(a) at an aerodrome in accordance with procedures notified by the CAA; or
(b) at a landing site which is not an aerodrome in accordance with the permission of the CAA.
which ShyTorque alludes to.
To answer the OP's question, I know of no relevant precedent.