I have read posts of D loops slipping and one had done this to me also. I was wondering if anyone has ever used the constrictor hitch for tying a D loop. It would seem like a natural knot for a D loop. For anyone that doesn't know, it's almost impossible to untie one after it's tight and the harder you pull on it, the tighter it gets, thus the name constrictor. Here is a picture of one. The one on the left is a regular constrictor and the one on the right is a double constrictor. As you can see you can still fluff the end and burn it just like a normal D Loop.
Anyone ever try this?