I'm not sure why exactly, but in the C:\Program Files\Norton Internet Security directory there are 2 sub-directories: Branding and MUI. Both of those contain a 16.1.0.33 directory, but no 16.2.0.7 directory. The Engine directory contains a 16.2.0.7 and correctly removed the 16.1.0.33 directory.
I'm not sure why the Branding and MUI directories weren't update or even if they were supposed to be updated, but it seems strange that they still say 16.1.0.33.