Problems converting MIF converted word document back to framemaker
I think the MIF file is basically a text file. Once your "friend" opened the MIF in Word then saved it as a Word file, the MIF text was wrapped in Word dross. You could try saving the Word file as text, and rename it as something.mif. Have a look at a MIF file and you'll see the first line look something like <MIFFile 7.00> # Generated by FrameMaker 7.0p578.
If you make sure that your Word to txt file has this type of line upfront, you might have a chance of recovering the MIF contents. Not guaranteed though. Hope you never have to do this again after you've spoken quietly to your "friend".
Just out of curiosity, why are you distributing MIF files to people without FM?