Hook up or fall down
The rules for "above" work in Germany required harness wearing when closer than one-meter to the edge above a fall of more than one-meter.
There's some other meta data--this happened in 2011! And it is being litigated in Criminal court. Who is in the dock? A supervisor or manager? Did they tell the engineer that it was safe, or had to be done, right now "Don't need to go back to the truck for the harness????