Yes, that may happen. The success of undeleting is uncertain. That's inherent to the mechanism. And it's why Microsoft implemented the recycle bin.
You can try to rename the .doc;0 in .doc, and that's about all you can do.
And, by the way, such things happening is why some people do a regular BACKUP. They copy their files to CD or DVD or an external hard disk or another PC in their home network or even a USB stick. If anything happens to the original, they simply retrieve (the official term is RESTORE) the copy from the backup.
Other people don't do that, and have a much greater risk of losing their data. Their choice.
Kees
Hello,
I have some files which I retrieved with undelete. Most of the files recovered ok, but some of them came back with the data either all ***** and a second file with the same name, but as a doc;0 file type. If you know of anything that may have caused this and a way to recover the data please let me know.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic