I'm not sure what happened as I wasn't following that thread. I did read the post from the owners that the foal went downhill or was stillborn but then the mare passed as well. That's all I remember reading. They weren't specific as I recall.
It tells what happened that caused them to lose the foal, but not why they lost the mare. One post said she looked as though she was having trouble controlling her hind end, and then nothing else was ever said.