I'm sorry, but I beg to differ. Although I think I spelled the case out for a small 'illogical linear hole' fairly well, for the sake of argument, I see a plot hole as being any illogical, unexplained, implausible or inexplicable event that results in an inescapable or seemingly 'predetermined' fate.
So are the extra magic missiles Immy has accountable? Well, I'll see what others think before coming to an absolute verdict, but as it stands for me, they are unaccountable in the game so far. Thus, again I nitpick, but it can only be an unexplained plot hole unless her belt is an unidentified belt of magic missiles or some crazy little thing like that.
I'm sure one could come up with other rationalisations for it as well.
But furthermore, I don't see how by passing the first encounter with Irenicus or another script line to allow one to prevent Imoen being taken away should induce a plothole, as he doesn't tell you anything integral to the story nor would anything be missing or unexplained. Unless you count the quest to track her down, which would be unnecessary obviously.
I've mentioned this one before ages ago on another forum I think, but another plothole I remember from my previous game involves the time-period during which the party approach Bodhi's hideout to kill her.
In this final encounter, no matter what time you approach the area - it is always nightime. One would think that if you got up at 6.am in the morning from an inn/area nearby, you could approach her hideout with a tactical advantage at your disposal - daylight. But no matter what, it is night and its obviously in her favour. I'm sure there's a cover up rationalisation for this as well to prevent whatever and so forth, but the fact remains that in terms of virutal world mechanics imitating reality, this is an illogical flaw.
Anyway, enough banter for now. Interesting to hear other thoughts.
Cheers,
Cerebrodragon