gonso,
Green sys hydraulic's (used for gear exension/retraction) powered by engines 1 and 4. With eng 1 Shutdown, I imagine EDP on engine 4 would provide more than enough power to retract or extend the gear.
Can you remember if the centerline gear was extended when you viewed the footage?
The centerline gear stays retracted when the free fall extension system is used.
Note: CLG does free fall on A340-500/600
3my
edited to add note