I am currently certified to operate on the 737, 777, A318, A319, A320 and A321. In the past, I've also flown the 757 and 767. And I can tell you that in this sort of situation, your worst enemy is not the aircraft make or type. It's the one thing that you welcome in an evacuation, but would happily kick around the airport when you've opened an armed door accidently. Lets hear it for good old power assist! That's where the 737 comes into its own. Whilst the 737 does not have the most dignified methods of arming or disarming the doors, the lack of power assist means that a door can, generally, be caught before it is opened enough to deploy the slide. And yes, I'm ashamed to admit, I speak from experience, following an incident occurring as we disarmed the doors. Luckily, the fact that I didn't have to fight to keep the door from opening, plus the resistance and very visible girt bar on the 737, saved us and our inbound passengers from an unscheduled nightstop.
On an aircraft fitted with power assist, by the time the brain reacts to the warnings, in whatever form they may be, it has kicked in and grabbed the door out of your hands. Think of it in terms of you shutting the car door, even as your brain is screaming that the keys are still inside...you swing the door and the momentum shuts it before you can react.
All the while humans are operating doors, accidents will happen. It doesn't help that many distractions are likely to be present at this time. Passengers standing up and dropping their duty free vodka on their neighbours head, pilots possibly braking heavily, crew from the back calling to confirm their doors are in manual, low crewing levels leaving one person alone down the front and of course, the biggest distraction of all, tiredness.
I'm all for minimalising the risk, but, no matter what you do, people will make mistakes. The only hope is that no one gets hurt when it happens. One thing I will say though...touch wood...you never do it twice!
Jsl