I was still working at the time, although maybe not at the exact time, and I recall nothing about this "incident". I know my aged brain is knackered but I can't help thinking that West Drayton, which was infested with civil and military ATC types, would have been humming like mad if such a thing had occurred. If an aircraft radio-failed in the approach sector it would not be wholly unknown and I don't think ATC would have pushed red buttons. And just how quickly could a fighter get to the scene?
Maybe there is someone out there who was on watch at the time and can answer one way or another.......?