Welcome to WebmasterWorld Guest from 126.96.36.199
In our case, a site with Penguin Flu never showed any relocation in WMT's, and stayed in the health order it was always in. However, last week, we used the link disavow tool, and the site immediately moved to the bottom of the list when sorted by health.
As if Webmaster Tools didn't know the site's health was poor until you submitted the Disavow list for it.
Delete the messages in WMT associated with a site and i immediately goes from "bad health" to "good health". Meaningless...