I don't think the designers expected players to spend massive amounts of time trying to find tiny loopholes in the rules to exploit in unanticipated ways. I think they expected people to just play the game and have fun.
I do think that the concept of a "game state" probably was on designers' minds, though, even if they didn't think of it with that exact terminology. "Immediately" typically means (not just in Descent, but in games in general) before something / anything else happens. The concept of a "game state" is merely a more technical way to describe this idea, and I've found technical precision in language to be useful for communicating ideas without misunderstandings on these forums.
I do agree with Thundercles that there are loopholes that either side of this discussion could exploit - like most things in Descent, there's no 100% definitive right answer. And I think James is correct that we've both managed to explain our reasoning pretty well at this point. So I'll accept the cease-fire proposal and move on to other threads.