That is absolutely correct. It seems you understand the meaning of the word very well.

[When she pushes about Ryoji's past, though, Diarmuid's happy expression fades. There is no way he can think of that she will understand what Ryoji had to do because of Nyx and trying to explain even parts of it will likely not turn out well.]

He did nothing wrong and made no mistakes. Unfortunately, someone tied to him was fated to do bad things, and he feels like it was his fault and his responsibility. That isn't the case and he did all he could to try and help.