Who Does Not Cause Sybil Vane's Death

In this quote, Oscar Wilde is making an analysis about the cleverness Dorian’s character has, when he uses his eternal beauty and youth in his favour. This is clear when James Vane goes to Dorian and affirms he is going to kill him in revenge of what he did to his sister, Sybil, who committed suicide eighteen years ago; so if Dorian was the correct men to kill after all those years, he would appear older than forty years old, as James Vane expected it to be . But in that moment, Dorian remembers he has the face of a men with less than twenty years old, so he claims to James to put him under the light so he can see the appearance of his face, and make this rebellious brother to think he clearly didn’t cause Sybil Vane’s suicide, because of
the inconsistency about the years of the event and his appearance of age . Regarding this past situation, when the lady at the bar makes James Vane realize Dorian lied to him, Wilde is pointing out how clever this man is to omit Vanes’ reasons to kill him, by the means of his immortality, when his life and dignity are attacked by someone he can’t honestly defend from .