git mergetool documentation oversight?

Having just tripped over this, it would be helpful if the fact that git 
mergetool saves the merge-conflict version of the file with a .orig suffix 
and that the file should be deleted before adding and committing the merge 
(as described at 
http://gitguru.com/2009/02/22/integrating-git-with-a-visual-merge-tool/) 
were documented on the git-mergetool page.

Chris