Devils finger / hand is loosing fingers

This is something that started showing in the last few weeks and it is puzzling me. This is one of my older corals and has always done really well. Looks like some kind of yellow leather, but got sold to me as a devils hand or devils finger. It can get smaller then your fist when agitated, and two/three hands wide when all blown up and with polyps extended.

Two weeks ago I found a frag of him which had attached elsewhere in the aquarium. I didn't think too much of it at that time and just gave it to another member of the club. Now, in the last few days, another one of the "fingers" is kinda dangling, looking to be letting loose from the main body. The main coral and the finger are still blowing up and seem to be feeding.

Finally to my question: Is this its way of propagating? Or is there a sinister coral ripping/eating creature at work? Or is it maybe sick?

Many times coral will self propagate.  This has been documented many times.  If there is only one finger doing this and it slowly falls off then most likely this is self propagation.  If you see the flesh eroding and more the one part of the coral is affected then this is usually not propagation, but it is usually the start of the end for the coral.