Hahahh, I think you were one of the first people to actually discover that "easter egg". When we first introduced the secretary NPC to our internal play-testers she didn't have any behavior, yet EVERYONE tried to punch her (I guess it was that she wasn't even moving as opposed to everyone else). Sooooooooo we decided to surprise them upon next release with that, and it seemed to be a hit!
We recently updated the game so that it's no longer an instant game over, but it's still a 1 hit KO!
Also, it IS possible to dodge roll out of her slap... it's just really hard (like 2-3 frames). I've only been able to do it about 2 times in a row.
Thanks for playing!