FCC's (Flight Control Computers) and FCU's (Flap Control Units) are powered by 115vAC STBY PWR and 28vDC main BAT BUS and most bits in the flap control systems have AC and DC CB's as do a lot of systems, so as long as you have STBY PWR and 28vDC power a lot of systems still work, and are indicated on the EICAS screen that is still powered. As the a/c still had HYD power and Pneumatics (eng's were still running) then flaps LE and TE will still operate. The assymentry occured after due to various things being out of sequence (to keep it simple)
Do not be confused with primary and secondary electrical control/operation of flaps this is an entirely different system and in this scenario were not used.
Gear is a similar scenario, electric motors are use to release the gear locks and through cable linkages and gravity doors are release, pushed open and gear falls down and locked by geometric locks, doors stay open.
p.s. I have many hours experience of unblocking drains, normally cause by the CC putting Red Wine and Milk down the drain which funnily enough congeals in to a large imoveable blob, even though we have big signs on galleys that they (CC) are not supposed to pour it down there. So poor maintenance - no, poor CC maybe, we shall have to see.