There are a lot of things about that advice that don't make sense to Kaworu. His brow furrows. "Are you sure?" He didn't force Frisk to come.

And it's not like there won't be other dangerous situations. What is he supposed to do if it happens again? Doesn't apologising mean it's your fault? It's taking responsibility for what happened. But he warned Frisk ahead of time... what else was he supposed to do?