Why am I allowed to delete moderator-only tags?
Check out the revision history for this question. Revision #3 consisted of the addition of the restricted, moderator-only red tag — hurrah for search keywords —
[status-completed]. In revision #4, the OP rolled back to the original version of the question, which stripped off the restricted tag.
I am not clear on whether this is possible for any rollback-enabled user or only the OP. But either way, this seems like a loophole in the moderator-only nature of restricted tags; non-mods shouldn't be able to remove restricted tags.