"If you can't see flames but only limited amount of smoke (hence not so dense you can't see through it), then it's hardly clearly catastrophic and there is time to think"
Ever been in a fire?
I was in an office (in London) once and a few whisps of smoke came through the floor - within 10 seconds the place was so full of smoke you couldn't see your hand in front of your face
if you see smoke GET THE HELL OUT OF THERE
I suspect in this case the pilots where wrapped up trying to figure out what might be wrong and just didn't pay the CC any attention when she poked her head around the door
Sure, she should have said something to get their attention but she was down back and they were up front - better to have 4 minor injuries than a blazing plane full of people