IN response to some of the comments made,
Airbus' doors are known within airlines to be easier to inadvertently blow a slide on due to their design
Anyone who's seen the inside of the 767 will see its the only Boeing Door that doesn't open out, but rather rolls into the ceiling. They will also not that the arming lever and door handle are right next to each other. The reason Boeing ditched the door design was because it has the highest incidence of inadvertent slide deployment in their commercial fleet
Every airline goes through phases of slides being blown more frequently than normal. This is usually attributed to new aircraft types in the fleet or changes to SOP's
Crew are human and can be distracted by passengers, things going on in the cabin, or just tiredness at the end of a long day. I have almost done it and Im sure others have. You're starting to flag and when you go to disarm, you see the handle marked pull and want to pull it, then luckily catch yourself before you do
Pilots make mistakes, so do we!