Winterbourne did not take responsibility for his misdeeds. All the time, he was aware of his influence over Daisy. During the first part of the story, his words and actions lead Daisy to believe that improper conversations and going out unchaperoned are nuanced in Europe. Since Daisy has never been to Europe, the result of his behavior led her to assume that things are done this way.
He saw her so long; it is conceivable he was gazing at her inconsiderately. “He concluded he should progress farther, instead of withdrawing” and keeps on addressing her, and when he sees that she appears to be unembarrassed, he expects that she may be a “flirt.” It was he who additionally set up the chain of occasions that drove Daisy to act mischievously. He showed her some unacceptable perspective on habits in European culture and persuaded Daisy to think that he genuinely focused on her.
When they go off together to the Castle of Chillon, he tells her how cheerful he is. She, thus, get some information about himself and his family, his preferences, propensities, and expectations. Winterbourne’s sentiments where shown when he doesn’t change his arrangements to return to his paramour in Geneva. His takeoff made Daisy annoyed and disillusioned.
Winterbourne was annoyed at Daisy’s behavior (of her seeing Giovanelli) and continued lecturing her about her reputation, which angered Daisy more. The final confrontation between them was when Winterbourne declared that it doesn’t matter whether Daisy is engaged or not. And neither her reputation nor her affections meant anything to him. For Daisy, if Winterbourne did not care for her anymore, she would no longer care for herself. Her death is the ultimate proof of the fact that her actions depended on Winterbourne’s faith in her.