Nowadays you can be sure that - in ANY evac - many of the PAX will have hand luggage with them. We have seen this in BA38 (low impact) and even in Asiana 214 (high impact).
No one listens and early, uncommanded, opening of doors does not surprise me. Frightens me, but not
I wonder, if you were in a similar situation, and your cabin bag held your passport / documents / money etc, unless there was some serious fire, whether you would gladly ditch all and run or make an effort to pick atleast the bit valuable, forget the checked in cargo ..