I was unfamiliar with this case before watching the Dateline special on 9/18/09. After watching this, I felt a need to write and see if it was called to anyone's attention that the addition of salt of any type (Bath salts, epsom salts, sea salts - common additives in bath products) to bathwater can greatly reduce, perhaps even negate the effects of pruning to the skin.
From Wikipedia:
Salts change the osmotic balance of the water so that less water is absorbed by the skin via osmosis. This reduces the "pruning" or "wrinkling" effect of prolonged exposure of skin to fresh water.
If Sarah was using a popular, yet common brand of bath salts, she would have experienced very little pruning to her fingers and toes.