An Aes Sedai can tell a lie if she believes that it is the truth. Verin exploited the loophole and was able to bypass the Dark oaths. If she was saved of the poison, she would not have been able to betray the Dark One further. But the betrayal that was done cannot be undone. It is a weakness of...
One of the most emotional parts for me is Moiraine's battle with Lanfear at the Cairhien docks and Rand's reading of her letter. That's quite a few tissue papers. The steadiness and bravery of knowing that tomorrow will be your death; and still being collected and in control so as not to hurt...