Interesting. From the video, I'm curious why you pulled from a "wide" angle? It looks like the angle of the line hooked to your come along was about 90 degrees or so. At that angle (or wider) you start to put a lot more force on the pulling line than on the sling/stump you were pulling. When I set up a 2:1 MA on my Maasdam rope puller (giving me a theoretical 20:1), I try to keep that angle as small as I can do safely. (I don't like pulling trees/stumps/branches/etc straight toward me). Making the angle wider decreases the MA on the stump. Not much of a decrease until the angle starts to get around 90 degrees. Much more than 90 and the loss of pull gets dramatic.