Narrative:

Mechanical on first airplane after passengers boarded. We changed airplanes pushed back and returned to gate due to mechanical on second airplane. I got out of seat and went to door 1R. Slight delay in waiting for jetway and disarm door announcement. I did the stop drop and review procedure before hearing the announcement. I knew I was disarming door. Then somebody said something to me and I think the interruption broke my focus and I may have gone into arming procedure (but the door was already armed). In trying to push arming lever release button in (it was already in) I caught my finger in the groove surrounding the recessed button. In the struggle to free my finger/fingernail I must have become confused and inadvertently activated the door handle. The door started to move in and up and my first reaction was to try to stop it but I knew I couldn't and I stepped back and held on protected myself. The slide fully inflated. I looked down to see that no one was there (thank god). I stood guard at the door. The purser made an announcement asking people to remain in their seats. I continued to guard the open door until all passengers had deplaned.

Google
 

Original NASA ASRS Text

Title: B767 Flight Attendant inadvertently opens an armed cabin door [1R] after a return to the gate for maintenance after previously swapping aircraft for a different mechanical problem.

Narrative: Mechanical on first airplane after passengers boarded. We changed airplanes pushed back and returned to gate due to mechanical on second airplane. I got out of seat and went to door 1R. Slight delay in waiting for jetway and disarm door announcement. I did the stop drop and review procedure before hearing the announcement. I knew I was disarming door. Then somebody said something to me and I think the interruption broke my focus and I may have gone into arming procedure (but the door was already armed). In trying to push arming lever release button in (it was already in) I caught my finger in the groove surrounding the recessed button. In the struggle to free my finger/fingernail I must have become confused and inadvertently activated the door handle. The door started to move in and up and my first reaction was to try to stop it but I knew I couldn't and I stepped back and held on protected myself. The slide fully inflated. I looked down to see that no one was there (Thank God). I stood guard at the door. The purser made an announcement asking people to remain in their seats. I continued to guard the open door until all passengers had deplaned.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.