You're right there are other things that may happen at the time of arming and disarming a door that's why we need to be extra vigilant and aware during this time.
Having operated a lot of flights that arrive in the early hours of the morning after a night of back of clock flying, I always take a few seconds to stop and think about what I'm about to do before I touch the door.
Complacency I'm sure is a contributor to slides being blown in regards to your question Judd.