Nothing is foolproof.
Always have a plan B, or an option behind door number two.
My plan B with the Slingshot Sure-Fire release is ditching the wrist leash, attaching the kite leash to a Wilchard mounted to the harness.
I've been using this set up over a year, ever since the wrist leash was ripped off my arm in what I consider underpowered conditions.
There are a couple of options:
1. Hook the quick release to a caribiner clip attached to the metal ring on the side of the Dakine harness'.
2. Hook the QR to the spreader bar. I'd rig it to the spreader BAR and not the hook. If your hook breaks, yer fizucked losing both the kite and leash.
3. Fashion a grab strap of rope to the back of the harness and attach the kite leash to a length of rope with a bowline at the distal end. The bowline will travel the length of the grab strap rope allowing handle pass tricks without the leash getting wrapped around you.
Hell you can even put the QR somewhere on the line for a last chance to bail out.
I will be switching to option 3 when I get my '04 quiver.
When I can afford $210 for the Advanced SKRU [swivel quick release unit]
I'll attach the leash there. http://www.advancedkite.com/AKE%20Shackle%20about.htm