I wouldn't say you were particularly lucky to survive or unlucky to be on that flight, things on aeroplanes fail from time to time hence the built in redundancy in systems.
A few points from your post:
There is no fuel dump facility on A320 a/c so land overweight if in a hurry or if you have the time fly around and burn some off.
The noise you heard (which some people often think is a dog barking) is the PTU, it is a hydraulic motor that can transfer hydraulic pressure (not fluid) between 2 of the hyd systems on the aircraft. If the logic in the system detects a pressure drop on one of the systems (Green or yellow for you spotters out there) the PTU operates and maintains system pressure. Operating a heavy user fed by that system is enough to enable this IE flaps.