The fact that the handwriting is the same does not mean the enumerator was the same person. Check the name at the top of the sheet to be sure.
The handwriting could be from the same copyist, because most of the census images we see on film are NOT the originals. Copies were made to be sent to Washington, the originals kept at the local government level. This varied from year to year, but 1870 was one of the years of at least three copies being made.
The original census pages were often destroyed by the county or state, although some have been found. As you can imagine, pages carried around on a summer day and filled out with ink would not be as neat as the pages we see on film!
William Dollarhide has written a book on the history of the census which explains this copy system and identifies the years we can expect to see original pages (usually the early ones).
Actually it could be that the same man did list the same family twice; I have found this a few times, usually in rural communities where young people were "working out," and were counted at their workplace and at home. or a young couple newly married who were counted at both their parents' homes. Weeks could have passed between the two enumeration days so he could have forgotten he counted that family already, and we never know who answered the questions about the "folks next door."