Well, it certainly was an interesting experience! The production team were a pleasure to work with, and we had plenty of practice before the 'event' which refined some unknowns.
The CASA approval was dealt with admirably by our Ops Manager, although everything slowed once it left our FOI's desk: I suspect no-one wanted to be associated with it! CASA actually have an internal guide paper on bungy jumps, so we met their requirements and got the tick in the box.
The bungy crew came from Cape Town, and had previous experience from an S61N, and a Puma, totalling 7 jumps in all. We were set 1000' as a minimum height, but this was really too high as the jumpers then finished up 500+ feet above the water, and had to be flown down an excessive amount before landing. Deadweight drops showed up a couple of issues, the first was that a perfect hover results in the drop bouncing vertically, and bouncing, and bouncing, and: you get the picture! For static (bridge) drops, the anchor point is 30 metres from the jump position, to induce a swing that helps damp the rebound. To emulate this I had to shift the BK117 left and back as soon as the jumper left the helicopter, then hover and allow a swing. Looked a bit untidy, but worked well. There was no effect on the helicopter at all from the jumper leaving (backwards, facing into the cabin), nor from the rebound.
Lowering the load is just like a normal long line, right? Very, very
wrong 
Ignoring the marshalling signal to hover, I put the first static drop neatly on the ground, only to watch it neatly lift off and land 10 feet away, then lift off, etc! The bungy cord stores a mass of energy, and even in the static mode it will stretch almost twice its length with a load on the end. As soon as the load touches the ground that stretch wants to dissipate, so the trick was to dump the collective and drop 100+ feet as soon as the load first touches, which always results in a smooth landing for the jumper. Not something that I even thought about, good job we had plenty of budget to practise
Due to the small door area in the BK, plus to help lateral balance, we put one bungy crew in the left door, with the jumpmaster and the jumper in the right door. The cord weighs about 40kg, so it is held by the bungy crewman until the jumper exits, to avoid the weight pulling on the jumper's harness and upsetting their balance. All the usual safety measures were in place, with the cord primarily off the cargo hook, and a safety line in place to take the strain if the hook failed. Safety knives all around to cut the lines if needed, jumper had one too, plus lifejacket and 'drop bag' with a line to lower when 50-70 feet off the ground.
There's a video cut of one jump
here on the ITV webpage, and many thanks to those in UK who offered to tpe the show. I understand ITV/Granada even gave credits at the end, they must have read Rotorheads and noted our comments in a previous thread! Total "live" drops were 15, with a couple of deadloads before, so we were lucky enough to rack up a decent bit of experience: anyone needs advice on a similar operation, just ask
The cord:
After the first "live" drop
from the cabin: it's a long way down
