After all, the possibility exists that it may simply be an unexpected lateral gust...
There was damn all wind in any direction ....
I have to ponder just how significant such vibration would be compared to that which might be expected from a damaged engine as suggested by the warning systems.
But engine 2 had no real internal damage - in fact the BEA report says specifically that the internal state was not such as would cause surge. Equally there is no mention of any
engine failures that might give rise to a genuine fire warning from flames inside the nacelle.