Strip lighting fires

I have recently investigated a fire where one of a number of contenders for the cause was a strip light fitting. It was a twin-bulb self contained unit suspended by 2 wire anchors 2 metres below the structural ceiling in industrial premises. the top housing was of fire resistant glass fibre re-inforced plastic. The diffuser was easily flammable with the formation of burning drops. All component parts (capacitor, ballast etc.) were mounted on the upper surface of the central steel tray. The bulbs were slung beneath the tray. The whole unit forms a well sealed compartment with no dust, fluff or animal litter inside.
We all know that strip lighting can be a cause of fire but in a self-contained, hung unit like this I cannot find any feasible means whereby a minor component overheat or fire on top of the steel tray can transfer fire to the flammable diffuser. The fire service investigator (overseas) was of the opinion that if one component part was burning the heat contained within the housing could transfer fire to other component parts. He had recently attributed a fire to this very cause and scenario. I ran a number of tests on control samples at site and will write them up for the IFE site in due course.
Any views or opinions?