You uninstall SEP through Programs & Features with the intention of removing all SEP-related entries from the machine.
However in Task Scheduler, three tasks still remain:
SEP 14.3.*
This is known behavior with the 14.3 build.
1. A fix is underway for a future SEP build.
2. Running Cleanwipe will remove these Task Scheduler items.
3. Please contact Support for an alternative fix to remove the entries from Task Manager.