but could someone explain to me what the 'order of events' is in the immediate stages of an evacuation?
Exact sequence may vary from airline to airline and from one aircraft to another, but the basic sequence is along the lines of:
1. Parkbrake set ( because we want to make sure we're stopped and stay stopped)
2. Shutdown the engines. ( Don't want people being sucked into engines or blown away by jetblast)
3. Initiate the evacuation using the PA, warning of any hazards if appropriate, and then also trigger the evacuation alarm. Alert ATC/Ground crew.
The seatbelt sign gets left alone. If you don't hear the PA from the Flight Deck, you would certainly hear the evacuation alarm..and you would most certainly hear the cabin crew...