Description of problem:
The POSTIN script in the policy package unconditionally executes
load_policy to update policy in the running system. However, if the
systems does not have SELinux enabled, the script fails and the
uninstallation of previous version of the policy package is not
completed and the package record remains in the database.

Replacing
/usr/sbin/load_policy /etc/security/selinux/policy.15

with
[ -x /usr/bin/selinuxenabled ] && selinuxenabled &&
/usr/sbin/load_policy /etc/security/selinux/policy.15

should fix the annoyance. I guess there is similar problem in the
policy-sources package.