"a sole blithering lunatic who had lost his nerve...”
"his snotty nose, the harsh chest pains, and the tears in his eyes..."

Thinking about that now. I gather the Silmarillion account of that conversation is to be taken as heavily edited.  I tend to assume the same thing. I suspect one doesn't really want to know exactly what Feanor said to him, if he thinks his brothers couldn't have taken it!