Maybe this helped. But it took 18 minutes to evacuate.
The FAA certification for that plane requires 90 seconds according to the WSJ article. The article also has details of how they run the 90 sec test. (dim lighting, debris in the aisles, various age groups by gender)
The tests are an expensive and critical piece of the certification process. Airbus and Boeing recruit hundreds of volunteers to act as passengers on board with at least 40% of the participants required to be female, 35% over the age of 50 and a minimum 15% both female and over 50. Three life-size dolls must be carried to simulate real infants aged 2 years or younger.
Cabin luggage, blankets and pillows are also required to be strewn across the floor to create minor obstructions, and the lighting in the cabin must be dimmed to simulate the conditions of a catastrophic event. Only half the aircraft’s exits can be used—for the A350, that would mean four of eight—and passengers aren’t given a warning of when the evacuation is set to take place.
Mike