Operator group and reboot cmd

[rank1seeker at gmail.com]

11.1 REL-p6

As a non-root user and member of operator group, I was able to issue a
poweroff and shutdown commands (group set to operator), but not a
reboot (group set to wheel) command (Operation not permitted).

I was able to reboot by:
$ shutdown -r now

But to use reboot, cmd I had to:
# chgrp 5 /sbin/reboot
# chmod 4554 /sbin/reboot
    Shouldn't this be set by default install?
# exit

$ reboot