The vast majority of people don't understand how this is possible. I feel sorry for that lady, as well as the radio station people.
Especially in the Ssouth Pacific zones.
I believe the tablet were pure salt?
WWII salt tablets - Google Search
Standard List Of Medical Supplies Issued to U.S. Merchant Ships During World War II
That happened to me when we hiked to the bottom of the Grand Canyon. It was so bloody hot, etc that I kept drinking water. The more I drank, I couldn't understand why I didn't start feeling better. I participated in sports since I was 4 through college and had never had a problem like that before. Luckily we signed up for the steak dinner down there and I got some food, pop and peanuts (lots of peanuts) in me.
I'm taking a shipboard medical course right now- the other day the instructor said that sports drinks should be diluted 3:1 water to gatorade- the sugar in those drinks prevents rapid uptake of electrolytes in cases of moderate to severe dehydration.
Glad nothing terrible happened to you. Very few people know that too much water can kill.