I will have to look into this. I have not tried to configure anything via the command line for the Macs. In the meantime you should also be able to disable OAS in the EPM console UI.
Another quesitons if you don't mind me asking. Is why you would want to shut down OAS? If you are having issues, with OAS and another application you can add it to the exclusions in the EPM console UI. I would not exclude it form ODS, just OAS.
Open terminal and run the following command:
sudo /usr/local/McAfee/AntiMalware/VSControl stopoas
Open terminal and run the following commands:
sudo defaults write /Library/Preferences/com.mcafee.ssm.antimalware.plist OAS_Enable -bool False
sudo /usr/local/McAfee/AntiMalware/VSControl stop
sudo /usr/local/McAfee/AntiMalware/VSControl reload