In fact nothing less than partly murdering her.

This seems a very extreme effect to flow from Fyne's words.

But Anthony, unaccustomed to the chatter of the firm earth, never stayed to ask himself what value these words could have in Fyne's mouth.

And indeed the mere dark sound of them was utterly abhorrent to his native rectitude, sea-salted, hardened in the winds of wide horizons, open as the day.
He wished to blurt out his indignation but she regarded him with an expectant air which checked him.

His visible discomfort made her uneasy.
He could only repeat "Oh yes.