How to do this sort of ornamentation

I just listened to a video of Joey Abarta and noticed an ornament, which I totally need to know how to do. It can be heard at about 1:11 min into the video: http://youtu.be/RmJenbSTYE8?t=1m10s.
To me it sounds something like a ghost d variation but I just can’t figure out how to do it. Any help is highly appreciated.

You play Add d as you normally would but as you play the ds you keep your pinkie off and give just enough pressure to let the ghost d’ sound when you close the thumb hole between the ds

Thank you very much! It seems to work quite well, but you really need a very stable back d for it…