He'd said the wrong thing. As soon as the words left his lips, he knew it, but he didn't regret it either, because regardless of what Obi-Wan said, in the end, it was up to Faiza whether to trust him or not. She'd chosen not to.
"You blame yourself for everything, Obi-Wan," he said. Sometimes it was Obi-Wan's fault (like Renly nearly dying), but most of the time, things just weren't his fault at all. "In this one, there is no blame. There's only choice. If she's what you want, take your own advice. What I think doesn't matter."