I've not been near an MRA4, but I've been reliably informed that the exposed part of a hot pipe was/is(?) only a clamp and it was approx 30cm above a fuel feed pipe. OK, not a perfect design, but this was inside an engine compartment, where fire detection and protection existed. For that design to cause a catastrophic failure, there would have to be a fuel leak of sufficient pressure to spray upwards and impinge on the very hot clamp. The fire systems and crew drills would then have to be unable to extinguish the fire.
Engine compartments in all aircraft necessarily bring together the ingredients for a fire, which is why there is fire protection in those zones. Its the nature of the business.
So, lets not get too excited by headline criticism.
Having said that, it is a fact that the specimen production aircraft made available to the RAF engineers (air engs and ground engs) was significantly lacking in build standard. Their findings have been recorded and reported.
The safety case work, sponsored by the MOD as required by the new MAA before a MAR could be issued, had hardly started. There was no way that a MAR would have been issued anytime soon. It would have required the MOD safety case work being subjected to enormous pressure to stay on the existing delivery schedule.