Not in this case, but I've had it work loose. It's great for holding tension while you finish the knot, but I haven't had great luck with it staying long term. I'm gonna see how what I have works out. The reason the back looks sloppy is I worked the cord between the wraps, and I'm hoping the knots on the ends hold it in place, and maintain tension so the knot doesn't undo.
We'll see. I'm not super happy with what I have anyway. I needed to allow more space between the hole and the edge, and use fewer holes. I made holes, and then skipped them cause they were too close, and it threw my spacing off. I also want to get a hammered hole punch. My leather punch isn't stout enough to make a hole in the strapping without potentially damaging the tool. I made the holes with the awl in my knife, which left it rough, and made it tedious to work the cord through.