Wow, that is a terrible story and makes me sad just hearing about it. I thought that maybe they needed more Calcium (that's a common problem these days).
I have no clue what's going on with your plants, but hopefully if it is a fungus, it'll run it's course and run out of steem before too long.
Yeah I might try it again next year - after 4 years the garden might be clean from whatever it was affecting it.