A few more answers from Singapore
A few things from my perspective.
(1) SQ did give a press release, it was in the local press here. Basically engine caught fire on landing, fire put out in less than 5 mins, passengers disembarked with no injury. Full stop. The lack of evac was also questioned in the local press (not by SQ of course).
(2) You cannot write off the China Air as being irrelevant because the ARFF took 5 mins. The plane exploded well before that time and the passengers would have been toast at 3 minutes in. By 5 mins it was a burning wreck.
(3) it took slight over a minute for the fire services to arrive by my reckoning. Now add 90 seconds for an evac, and you are at 2.5 minutes. Check China Air at that time stamp!
(4) My impression is that the first flames are aviation fuel, not oil. Not enough smoke. Maybe oil gets involved later on. Someone suggested that the pilot forgot to stop dumping fuel, that I think is highly unlikely.
(5) As has been pointed out, these tenders do not carry a "motherload" of foam, just 90 seconds worth. And after 90 seconds of foam (so 2.5 mins after stopping), the fire was still at a dangerous level. So that is one minute after a full evac would have been completed.... As has been pointed out, a LHS evac would have been safe.
(6) my response to "an evac might have been dangerous" is, it is the job of the crew (front and/or back) to make a sound judgement PDQ. Not cross your fingers and hope the services put it out before it goes boom.
Luckily, thank god, no one was hurt. I would have accepted a few broken ankles as a good outcome too though.