The UK/US community no longer assuredly has effective dominance concerning radar and other (e.g. optical) stealth technology , nor on the control of off-the-shelf system components for RPAS construction.
The MoD , since 2009, has distanced itself from investigation of UAP ( Unexplained Aerial Phenomena) reports for justifiable reasoning at that time.
I would suggest that, since then, the "no threat " argument about the presence of possibly unexplained objects in our airspace seems to be increasingly complacent .
Specifically, I am thinking in the light of such recent events as possible "quad-copters" reported over 12 French Nuclear associated sites, conceivably associated with malevolent intent.
Perhaps the U.K should follow the French example and consider putting in place a formal structure for handling and evaluating such reports?
I am thinking particularly in instances when they may be opportunistically captured on still or FMV imagery and also not necessarily implying their investigation solely from within MoD resources.
( In France this arena is primarily the responsibility of the Gendarmerie, with CNES also maintaining a study group, with some additional indirect funding from Airbus).