Showtech did the rigging (or was at least heavily involved) - the rigger that is visible in that clip is Tiny Good (founder of Showtech).
Personally, I would have thought that a non-user operated safety brake would have been put in (something which triggers at a set distance from the end of the line), and that there would have been some rubber on the end of the zip-line to catch the runner and slow him at the end as well (cushion the blow as it were) as well as a rigger playing catcher. That said, I was not there and don't know the exact circumstances. One can only wait and see what WorkSafe come back with when the investigation is done.
Now THIS is how you do it. I've seen photo/vid of the MONSTER shock-absorber/stoppers at the end of these things. Dear Lord... YouTube - BOOTLEG CANYON FLIGHTLINES #1
I don't normally endorse this, but...oh, who am I fooling? I was reading my wife's copy of the new People magazine (Best of 2010, Sandra B on the cover) and on page 15 is a gi-normous photo of HJ on the rig, brake lever in hand, looking like he is having WAY too much fun. The rig looks totally bomber, so I will have to agree he was having too much of a good time and didn't get on the brake early/hard enough.
It happens in drag racing too. But that's why there are parachutes above 150 mph.
Not that far, but you can do the Freemont Street Experience on a zip line. If you want something more scenic, you could try the one in Boulder City by the same group.