Elizabeth looked archly, and turned away. Her resistance had not injured her with the gentleman, and he was thinking of her with some complacency, when thus accosted by Miss Bingley -- (Chapter 6)

The succeeding equally mortifying discoveries are listed in the same paragraph that you quote—there are two of them: He was wrong about her figure and he was wrong about her manners. After discovering he was wrong he began to wish to know more of her. After Lizzy refuses to dance with Darcy, he is thinking of her with some complacency—a smug satisfaction. At the end of the chapter Caroline teases Darcy about marrying Lizzy and he listens to her “with perfect indifference.” His behavior does not strike me as a guy who feels he has lost control of his emotions or fears the power a woman has over him. It seems to me his complacency about Lizzy and his indifference to Caroline’s teasing suggests he feels himself to be in no danger at all. ;D