Hi Nate and Skip,
when you miss a bar pass, or let of the bar for some reason the suicide leash just catches the kite, the bar flies up against the depower strap, depowering it slightly, and with the back lines now slightly loose the kite will either just fall into the water and wait for you to pull the bar back towards you and relaunch it, or it will stay in the air, in which case you just pull the leash in and hook back in. You do get a bit of a pull when the leash tensions initially, but as soon as you let go of the bar the kite will just travel in the direction that you were last pulling. You usually only get dragged for a few metres. Despite what alot of people say, this system is actually very safe IF it is used responsibly. I wouldn't be doing bar passes or any tricks were i may drop the bar if i was close to shore in an onshore wind with people on the beach, or if i had other riders in close proximity down wind of me. Think about it, if you missed a bar pass at 20-30ft and your kite fully depowered and turned into a flag you would freefall and more than likely injure yourself. With a suicide leash you would normally just float back down with the kite, as at this height the kite is normally above your head for a bar pass. One other thing, if your going to run this type of leash, make sure the suicide leash is strong enough to take the force of a big wipeout. Too many riders are using standard leashes for this purpose that were only designed for connecting to the depower line. Get a suicide leash made up by buying some 8 or 10mm spectra, pulling out the core and then threading some shock cord through the spectra casing. Make the shock cord a bit shorter than the spectra and get this sewn into place at each end, so you've got a bit of spring in the leash. Also, make sure you get a nice big stainless snap shackle, sister clips are very weak and chances are they'll pull apart in a big wipeout.
Hope this helps.