A question for Jared:
"...files are mostly duplicated with .Id_XXXXX..." Jared, is it possible that the recovery picked up all previous deleted versions along with the most recent version of the documents?
For example, I edited my advice.htm three times this week, both deleted copies and the currently saved advice.htm would be picked up by my internal data recovery software -- if I accidentally deleted the folder that housed advice.htm.
I have no knowledge as to why some of the nice person's files were corrupted, except to ask:
maybe a slowly-encroaching HD failure?
"Take care of thy backups and thy restores shall take care of thee." Ben Franklin revisited.