Poison isn't a delayed action, and wouldn't kill anything on its own. It just makes the target a bit easier to kill by future actions.
But yes, poison isn't going to give you a "kill credit" unless you're also the one who deals the death blow via other "direct action"
yeah but I prefer take this exemple too because some people could say, you killed the monster with the extra dammage my poison gives you so the kill is mine.
When I say deleyed action, I mean an effect that is not triggered immediatly. Like wound (start of each turn) poison(when an attack occurs).