Updraft, tangled lines, ... I can't tell exactly where the failure was.
Even when not opened fully the chute will still provide some drag, so it's not quite as bad as going off the cliff without it.
Re the comparison with climbing... When climbing, the rope is there almost purely as safety equipment. "Almost" because there's a specific call -- "tension" -- for indicating that you'd appreciate it if the rope was pulled up as hard as possible to help stabilize you while you do something you're not sure you can pull off. With that one exception -- and of course if you do fall -- the rope is, if anything, a reassuring nuisance; climbing you (and what you can carry) versus gravity and the rock.
Many years ago, I was climbing in the Gunks when I noticed that there was an ultralight flying by at about the same altitude. I looked at him, he looked at me, and I'm sure we were both thinking "he's got to be crazy."