On Fri, 1 Dec 2017 10:21:54 -0700, Bob La Londe
wrote:

The ring was installed backwards or maybe it was broken off on the end.
In either case the cap/plug absolutely would not turn out.

As I understand the video, the cap does not have any threads, so there
is no in or out. The locking wire can be installed either way. In the
video, Keith takes the wrong guess. The only consequence is that he
has to rotate the cap almost one full turn before he finds the end of
the locking wire.
--
RoRo