Not a pilot, but I checked all pages and nobody has looked into this before:
Does anyone here know the timing-specs of the temp sensors on an A330 ?
As all temp sensors has an delay-time of x seconds (average 10-40 sec if change is over 20 Celcius directly) before indicating the correct temp when major changes occur in temp, it may could be one more source to the trouble for this flight with all the previous details of this flight such as coffin-corner and flying into a cb area with possible warmer zones.
Edit: Enclosing footprint map of Inmarsat/Satcom were ACARS is used, have a look on the AOR-area, it may be possible that the flight also entered a poor-reception area in itīs final stages.
http://www.alphatelecom.ru/inmarsat/images/engmap.jpg