Not my sort of puzzle, I�m afraid. Pedestrian till the end, where there is an ambiguity, as Deviant says, over whether to highlight just the happier discoveries, or the previous one as well. Given that both are mentioned in the part of the sentence before the semicolon, I don�t think it can be conclusive.
I am pretty sure that the correctly highlighted words share the same structure, which would probably rule out robinruth�s interesting idea, and some of the other �red herrings� which have already been discovered in the clueing, but I find the latter by their nature undesirable. What is obvious to the setter may not be so to the solver, and it needs a clearer pointer than a structural similarity which is not hinted at, and has to be inferred from a previous discovery, to confirm what is needed. In weeks like this I�m thankful I don�t submit them.
A shame, really, because the wonderful quote was ripe with possibilities, and deserved better (he says as a solver). This week�s Inquisitor was a much more ingenious and, dare I say it, Listener-like challenge.