He'd been caught up in preparing to defend himself, that he hadn't realized that Tadashi hadn't been on the 'attack' at all. It clearly takes him off-guard; he blinks once, the anger in his face draining away like water through a hole in a glass.

And for a long few moments, the only thing he can do is stare back, those words processing over in his head. His gaze drops for some of those, brow furrowing in - consternation, perhaps. A trace of guilt, maybe, because this is the boy whose first thought upon hearing he was still inside a burning building was to go in after him.

"...I'll be fine, Tadashi."

No bitterness there, no defensiveness. Just...resignation, if anything.