I know it's a long time since this thread was posted, but I've nothing to do now as I'm a retired sparks, who still likes to keep abreast of comings and goings with regards to all things electrical, BTW I have just taken my 17th Edition course and exam and passed, hows that for sadness.
The Olive you are talking about was used as part of the gland to increase the connectivity with earth, as we all know the copper sheath was used as the cpc. I personally used loads of micc during my time, we were even issued with an instruction manual from BICC called the "Electricians Mate" don't know if it's still available, still got all my MI kit somewhere, strippers, pot wrenches, straightner, cable sizer etc.
Pete