A little reminder to all the speculative minds:
Based on best practice of any investigation, that there should be at least two independent sources to lift an ASSUMPTION to the level of FACT, the last known fact of flight MH370 is, that it disappeared shortly after IGARI from secondary radar. Almost anything that - reportedly - occurred later in the chain of events is therefore an assumption - best case - or false - worst case, as long as the plane is not found and its black boxes not analysed.
Inmarsat data: only a single source.
Primary radar information: not complete (e.g. no altitude profile given) and single source only.