Please see this:
Symantec Endpoint Protection for Macintosh Frequently Asked Questions
http://www.symantec.com/docs/TECH134203
There is a section on how to lock down Mac clients
Q. How can I lock down settings for SEP for Mac clients?
A. There are not many changes that the end user can make, but if you want to prevent them from disabling Auto-Protect (for example), make sure their group is set to Server Control:
In the Antivirus and Antispyware policy, under Mac Settings, for File System Auto-Protect, click on the padlock to lock it.
With these selections made, even if a user has administrative rights on their Mac, they will be unable to adjust these settings via the Auto-Protect preference pane:
Without the padlock clicked and locked in policy, an administrator-level account would be able to authenticate to make changes to settings: