Darcy is quite intrepid in stating his appreciation of Elizabeth's eyes to Caroline. I quite understand the idea of not mentioning it to Elizabeth, when he had no plans to follow up on the attraction. (Not that Darcy is always that gentleman-like to the ladies around him, by a long shot!) But, WHY did he mention it to Caroline?
Was he blind to her flirtations and maneuvering? Surely not!
Was he indifferent to the anger she would show in her behavior to Elizabeth, if she realized Elizabeth incited Darcy's admiration? Of course, he could not know that Elizabeth would be a guest at Netherfield for the better part of a week...
Was he trying to annoy Miss Bingley, ala Mr. Bennett getting Mrs. Bennett's goat?
Was he trying to point out to her that her actions had not bound him from seeing attractions in other women, i.e., warning her that her attentions had not captured his heart?
None of these possibilities seem likely. What do others think? Did Darcy have some motive for dropping this pebble into Miss Bingely's shoe?