It's the admittance that calms her down, in the end, because Katniss has her own pride and independance enough to know that admitting something like that would be hard for her. So she pauses in her tracks, head turned to listen to him before she shakes her head. Once out of the line of danger, this was easier too.

"It's fine," she muttered, as if the whole ordeal was already forgotten. "You're still an idiot, but I don't regret saving you. Somehow."