Many engine problems eventually (sometimes within seconds) lead to a bang and a flash of flame out the tailpipe. Such a flash is a secondary event and by no means a confirmation of what started it.
Thus, just based on a report of a flash of flame one can/should not conclude what caused it without further evidence.
The earlier report of the Qantas A380 simply reported the flame/flash as a result and tied it to the cause after other facts were known.
It's too early to do the same for this event