Someone on TrekBBS asked if it was true that poor ol' Mr Leslie, one of the longest-lived, red-shirted security guards in the original series of "Star Trek", was supposed to return from the dead - seeing how he appeared as Leslie in episodes made long after "Obsession"? That was the episode in which several guards were killed by an evil gaseous monster that sucks human red corpuscles.
The answer is, yes, the guy was more than a little concerned about his character being proclaimed dead, and the director of "Obsession" even promised him there'd be a scene where his body was successfully revived but, of course, it was never filmed.
Extras and two-line extras in television series don't usually get much say when their character is killed off, mainly because they're back next week anyway. We aren't supposed to notice that the same extra in TOS keeps playing unnamed crew in the background (let alone that he also pulls additional duty as an alien, or that he drives the 20th century truck that kills Edith Keeler).
When TOS scripts were being written in the 60s, noone ever knew which extras and which two-line walk-ons would be available for which episode, and the names were often added at the very last minute. Neither was it imagined that, 40 years later, we'd be analysing the episodes so closely that we'd realize that some extras played multiple characters in the one episode.
It was only due to William Shatner that Mr Leslie was even called the same name so often. Shatner dubbed "Leslie" by that name in honour of one of his own daughters (similarly, Mr Lemli was named for all three Shatner girls: LEslie, Melanie, LIsabeth) - and the actor who played Mr Leslie, Eddie Paskey, was Shatner's stand-in, so they did become quite close. Paskey had previously played a Starfleet character named Ryan in "The Naked Time" (and Connors in "Mudd's Women").
I've heard fans try to explain that Edward Leslie survives till the end of the series, but that poor Leslie Ryan, whom Kirk mistakes for "Lieutenant Leslie", due to their similar appearance, is the man who actually dies in "Obsession". Or is it Edward's lookalike twin brother, Ryan Leslie?
Similarly, Mr Galloway dies in his fourth substantial TOS appearance, "The Omega Glory", and yet seemingly returns in the final episode of TOS, "Turnabout Intruder". But he's not named in that onscreen footage, only identified by a misspelt end credit (ie. "Galoway"). The answer there is that lookalike Mr Johnson, the guy whom actor, David L Ross, played in "The Day of the Dove", is the guy who appears in the TOS finale - because Galloway is still dead.
Or did Doctor Phlox the Denobulan (of "Enterprise") leave some notes on cloning human beings for Doctor McCoy to follow?
Other fans have a different explanation. Supposedly, if you place all TOS episodes in stardate order, the two problems of the resurrecting security guards disappear. But I prefer my versions - and production order, very different again to original screening order, for watching my TOS episodes.