Actually, in my opinion the missive George sent to Caroline just before the end of the chapter will be the one that finally convinces Caroline of the depth of her indiscretion and the possible consequences.
If George had told her all that in the alcove in a cool, deadly calm tone of voice, she would have wilted then and there. To have him tell her he regretted raising his voice, but not what he said has got to be telling.
As usual, a well crafted chapter with lots to think about. George's handling of the Elgin's was much more his style, but then again he has no real emotional involvement with them.