Had a look at this on final last night!
600'/2 miles is very late and scary to find out you have thrust lock or thrust back-off.
The interesting thing is that you are required to achieve 2 gates on the CDA. 1000' should be fully configured in the landing configuration with the Vapp within 25 knots of landing speed and reducing. The engines do not need to be spooled up to approach power by this point but they need to be stable at approach power by 500'.
These guys must have (my thoughts only) realised they had this technical fault in that 1000'-500' segment which means they dealt with it extremely quickly and very professionally at a seriously time critical point.
Curiously my colleagues and I were comparing the differences between the Boeing A/T system and the Airbus Alpha protections. In this case, as the speed came back towards the stall, would the Airbus Alpha protections kick in to giver TOGA power? Bearing in mind the protections are NOT a function of Auto Thrust.
A backup thought for the 787 maybe?
Good luck to all the crew and pax.
p.s. As Nugpot (Topgun???) has discovered the Boeing system moves the thrust levers to give tactile feedback and an early indication that power is not coming up. The Airbus system just leaves the thrust levers where they are, does its thing and leaves you to guess the power setting.