Bug - NIS GUI can be stopped using task manager even though Tamper Protection is on

I've just found a bug: NIS.exe (both SYSTEM and user instances) can be stopped using Task Manager and also the associated service (Norton Internet Security in services.msc stops). I've checked this with EICAR test file and it seems that only the GUI closes, as it removes the test file, but until NIS is restarted using Autofix (executing: "C:\Program Files\Norton Internet Security\Engine\21.1.0.18\symerr.exe" /support from a command prompt window), it wont tell that it removed a security risk. I've checked the settings and the Tamper Protection is turned on. This is very reproducible, even after rebooting multiple times.
NIS was just reinstalled yesterday when I switched back from N360. I have totally uninstalled N360 before NIS: using its control panel remove option, then I ran Norton Removal Tool 3 times (rebooted after each session) and also manually deleted NIS folders from ProgramData.

 

NIS 21.1.0.18
OS is Windows 8.1 Enterprise Eval 32bit with all MS updates installed.

I've also created a video about what is happening: https://drive.google.com/file/d/0Bybo81wYTjpUbWxDOEdxM1JDQlU/edit?usp=sharing
("Leállítva" means Stopped in services.msc)

Please investigate this. Thanks.