No sidebar in finder when viewing DFS shares
What type of volume you're viewing doesn't have an impact on the Finder's display settings. You can toggle the sidebar in any Finder window by going to View → Show/Hide Sidebar or pressing ⌥⌘S.

The reason you're seeing it on one machine and not the other is that it likely got toggled at some point for that folder and the setting stuck. Finder does store view settings per folder, although it can be a bit inconsistent in doing so.