It was true though! He was too good. He could have easily insisted that Kai should have stayed right there. It would have been extremely valid even! Kai would have done anything Shinji asked, and the request he made went beyond them. So Kai was giving him a bit of a Look, because hey.

"That's true too," he ended up saying, letting his disapproving look slip back into a somber fondness. "I'd find you though, even if I didn't."