Stan, that seems a very likely explanation for what Sandra has described.
I think it's fairly common to find an image of a census page with the headings left uncompleted. After all, the enumerator would be submitting the whole parish or other unit as a whole with a covering schedule too which would list the parish, ward etc.
The way I would work out where the page came from, if I had one of those images, would be to do a search on Anc*y or FmyP for one of the names, and when I re-find the same page, either look at the "transcription" for the entries, or to scroll back (or forward?) page by page until I found the missing information. Family Search should also give the address for the census record (depending on which year).