He wants to remind her that's how he'd been planning to fix it, exactly like that, but he can see the moment it dawns on her, and it dawns on him at the same moment that she hadn't figured it out yet.
The sorrow and guilt and pain are replaced by shock, by emptiness, and he has to take a deep breath to try and steady himself. They aren't his emotions he's feeling at all. They're all hers.
"I was trying to make it right again," he whispers. The way it should have happened to begin with.