Sam didn't blame her short lived love for Lucrezia at all. he knew how fickle the dome could be, and how it liked to shake things up in people's lives. it was just another dome event, nothing permanent. The ones he really hated were when no one knew something weird was going on. Or when he was turned into a small child.
"Well, it happens that I love you a lot too, and I like hearing you say it, so you can say it as often as you want and I'll never get bored of hearing it," he told her. "Which is to say, I love you too, beautiful."