I'm not one who believes in conspiracies, except those supported by a substantial and confirmed set of facts. However this disagreement about whether an in-flight fire occurred prior to landing is rather puzzling. This link from AVHerald regarding this accident, contains a list of quotes with dates from the various authorities involved in the investigation.
Accident: Lufthansa MD11 at Riyadh on Jul 27th 2010, cargo fire, broke up on landing
I know it always takes time to sort out the facts related to an accident, it's just that this one looks a little odd, given the sources of some of the statements. In particular, I think the Riyadh airport authorities would know if an in-flight fire and emergency was declared, and if they dispatched fire crews before the aircraft landed. They also reported the aircraft trailing smoke as it can in for a landing. They also persisted with this set of facts thru Jul 29th, but no further comment from them (at least as reported on AVHerald) since then. Very interesting. The pilots are also quoted as saying they reported an in-flight fire.