These apps show battery consumption because they do actually run on background and perform some work even though they don't have permissions to run in background. I can provide a few examples.
- Outlook - Sync my mail in background
- People hub - Sync my account, contacts in background
- Messenger - Shows me push notifications
- Loco Music player - Scans my music library in background
The Games which I have background battery consumption are
- Microsoft Sudoku
- Temple run
All these games have Xbox live integration in common, and I believe that is the reason for background battery consumption. Also temple Run updates the list of Daily challenges in background. Games could perform such activities in background.
I believe that only apps which are marked as not allowed by the user are restricted in background. And the apps which don't have any such permissions, do run on background.
Most of their background activities are due to
- Account integrations
- Push notifications
- Scanning media libraries
- Live tile updates
- Application updates
- Applications sending data collected to their services such as diagnosis information