Kathryn Hays was not an extra because she was credited and paid as the episode's featured guest star. It said "Guest Star Kathryn Hays as Gem" right there on the screen. Nobody who gets onscreen billing is an extra, by definition.
Yes obviously she was billed--i think we've all seen the episode.
I was simply stating that I had counted 399 speaking parts and 1 non-speaking part that OBVIOUSLY was an actor.
For my own count I DON'T count the guy who played Kloog who WAS billed, because clearly he was a stunt guy with no lines.
I think the rule was, a stunt guy who doubles for another actor during a fight or whatever DOES NOT get credit, BUT if he plays the person thruout the episode and is NOT replaced during the fight he sometimes gets billed.
At any rate, my personal list has all 399 speaking parts and Hays counted.
Really want those last two names!
But thanks for pointing that out.