Having many hours in Herons I can sympathise with you on the asymmetric flap.
The Heron in Fiji was one flap completely up with the other extended to 40 degrees.
The reason was that a connecting bolt in the flap system was installed with the nut at the top, so when the nut undid the bolt simply fell out causing the split flap.
My American friend who had owned the aircraft some 3 year earlier was sued unsuccessfully for the accident.
Luck he was able to provide that Sunflower had done the maintenance.