I am working in my Hunter Safety Education Certification here in Il and we teach the Safety Harness portion quite thourghly. I as well teach through the training at my job to use a Prassic Knot to keep your self tied in ground to stand and then back to ground.
The only time you are not tied in is when you exchange over from one line to the other at the stand itself and then back, for only a microsecond. Saved me 3 years ago. I was only about 10 feet up but my boot slipped off the screw in step, (Muddy) and I fell. The knot stopped me as it is supposed to do.
Me and my family will keep this gentleman and his family in our prayers.