is it safe to use the auto-saved file when "An internal error ... writing imported graphics ..." occurs?

Hello,
I am using FrameMaker 16 over a network and regularly get issues, I think due to that situation. When the “An internal error occurred while writing imported graphics in this document. The file has been saved, but has lost some image data ...” occurs a file is written to disk with a random extension time-stamped at the time when I attempted to save. This file is noticeably smaller than the .fm file I am working with, however renaming the extension does open a file bearing some resemblance to the original, and with [at least some] of the images. 
Is it safe to use this file? The smaller size is concerning, however I would like to think it is useful in some way.

I have just performed a back-to-back, page-by-page test and it seems there is no definitive answer to just use the back-up. I was able to see the areas where I had been working (the work I lost was related to reconnecting referenced graphics from a donor file) and simply copied the known good elements into the other file.

Many thanks