If smoke is billowing into the cabin as the article suggests then the cabin crew cannot initiate an evacuation there an then as the aircraft could still be moving or indeed the engines could still be running. The best thing to do is call the flight deck using the emergency call there and then and hope for proper instruction. HOWEVER....If fire is clear in the cabin, then I would seriously consider initiating an evacuation myself!!! But then, it all depends on the situation and to make a judgement on this particular case all I can say is that I would have had to be onboard to tell.