I had this request several times, but as far as I remember the path isn't stored anywhere and if it is it is so cleverly hidden and encrypted I couldn't spot it.
In this cases (for whatever reason we needed them, this is a whole different story) we had to parse the filenames from the error logs and do something with it.
I have something to extract the Clip ID of a Centera stored document from the content referal blob, but that doesn't not help you, but if the path is somewhere it is there :-(.
Doesn't help... I know,
/Gerold