There is a WoB
Questioner
So how did Shallan rescue Kaladin when they fell in the chasm?
Brandon Sanderson
She did not. It was actually Syl, but he was in the process of breaking the bond, and so she was able to get some Stormlight to him. But that is what really set it really poorly. Like you can imagine, she-- this bond was really a strain for her to use at that point, so it was her. But doing what she did just about destroyed her, which is why you don't hear from her after that.
Salt Lake City signing (March 29, 2014)