From what the SCCM had said at a recent Refresher course, after speaking with the the FD she asked passengers to exit the a/c via the airbridge rapidly (a rapid disembarkation).
The rear CC not being able to see to the middle of a/c due to a haze (and people standing up) decided that is was better to evacuate via slides.
The SCCM had made a decision after speaking with the L/R4 doors crew and hearing their concerns (for a rapid disembarkation that is).
They had also made a decision on what they saw.
At the end of the day its a 15 page report that doesn't go into lots of detail and leaves a large amount of uncertainty in what everybody was thinking and what everybody did.
We can all say that we would do things differently and that she should be doing something a little simpler, we were not there and sitting in our warm houses with a cup of cha next to us with no mounting pressure, should not criticise.