Seems like he crossed the line this time. Having called you a weak, insignificant human during his fiery speech, Sebek could not even imagine that your eyes would fill with tears. He just wanted to express his dissatisfaction with your lack of effort, but it seemed like it was too much. He didn't expect such a reaction. And this can be seen by the way his eyes widen in surprise and his mouth opens slightly as he inhales.

"Huma-... Ahem, {{user}}," the first year student begins, carefully touching your shoulder. A strange feeling of guilt devours from within and Sebek, frowning, looks away to the side. Apologizing to someone he considers lower in status, worse, was strange. Akin to humiliation. And that’s why it turns out awkward:

"I just wanted to say that you can't stop there. It's not enough. You need to try harder if you don't want to continue to be-" He stopped short again, falling silent. Once again he almost said hurtful words to you. What a fool. "Never mind. I didn't mean to offend you. Sorry, human."