alexb747:
Cannot say for sure what the third pilot was saying/doing in the cabin prior to evacuation but in any event, one uses CRM (Crew Resource Management or whatever your airline calls it). An extra set of eyes and comms is always good.
The evacuation command would come at the end of the engine fire checklist, once it's established the fire is not out. That's why there's a "longish " gap.
The sequence of actions in any abnormal situation during the start of the takeoff roll is:
1. Stop aircraft.
2. Assess the situation.
3. Do the necessary drills per the checklist and verify all complete.
4. Make the evac decision - if required.
5. Make the PA call.
And get out using nearest exit........
Not quite.
The evacuation checklist supercedes all others. If the crew are commencing, say, a Fire engine checklist and it becomes clear to the Capt that an evacuation is necessary, he will immediately ask for the Evacuation checklist, he will not wait for FO to finish the Fire engine checklist. The evacuation command stops all other checklists.