Yes, I know the 767 has no pin, I was just correcting an earlier post about the order we're trained to arm/disarm.
A girl I know armed her 767 door and then immediately went to open it on her supernumery flight. Luckily the CSS was keeping a close eye on her and intervened. She raised the lever about half way up. Lucky.
Sorry, that's why I speculated muscle memory for a new CSM.
Obviously way off.