A320 evac command
In A320 emer evac panel, there is a toggle switch with positions capt&purser and Capt. The previous operator I flew with had the SOP to place this in the capt&purser position so that the cabin crew can initiate evac if they spot anything untoward in the cabin. The operator I have shifted to has the SOP to place this in the Capt position as they claim don't trust the crew to take an informed comprehensive decision. But again the SOP in the last case, in a scenario where the crew spot a life threatening situation in the cabin with no call coming from the cockpit side , is to initiate the evacuation from the cabin by pressing EVAC CMD on FAP.
My question is what is the relevance of the Capt & Purser / Capt pb when either case evacuation can be initiated from either side. And secondly what is the procedure followed in airlines across the world ?