Apologise? The word makes Tidus break out of his thoughts (was there anything else he could give Taiki?), confusion washing over his face, before realisation has him shaking his head.

"What? No- I was just upset earlier, you know." What he said, being upset at all- "I-- I know you did a good thing."

After all, he went and saved Saku. There was no reason to apologise for that.