It will be interesting to hear the outcome of this one. Many possibilities to look at.
On the topic of fuel contamination leading to dual engine issues, over a decade ago now, a Cathay Pacific A330 experienced fuel contamination. An amazing effort by the flight crew to get her on the ground.
https://en.wikipedia.org/wiki/Cathay_Pacific_Flight_780 or full investigation report here for those interested -
Cathay Pacific Flight 780 HKCAD report
Thoughts to the two pilots in making a full recovery.