so, what is a death rig?
If a rig becomes separated from you the angler through a crack off, a snag or the line parts after a take then there is a chance that this rig can continue to fish and catch.
Once the bait is taken, if a fish cannot separate itself from the lead then there is a chance that the lead could become tangled in a snag or some kind of debris and tethering a fish causing it to struggle, suffer, and eventually die. There is a chance that the fish could throw the hook and weight with a good head shake as we've all been done in this way at some point but should we take that chance? If we care about our quarry then no.
A good quality lead clip will drop a lead easily if set up properly and a helicopter rig when set up correctly should allow the hook link to slide off the leader without much resistance, an in line lead should be able to slide off a leader in the same way and anything fixed between the end of the leader and the mainline is a no no, especially quick change links and swivels, these may aid in a speedy setting up of tackle ready to fish but are not safe to use in this manner. In a similar way anything fixed to the mainline above anti tangle tubing such as a split shot or a twist of lead from leadcore can stop this from sliding free of the mainline.
I love to experiment with rigs and anything new that could give me the edge is always worth a try but the Carps safety has to be put first before the need to try the latest fashion in end gear. Something I always do is test my rigs safety, when was the last time you checked to see if the clip you use drops the lead as easily as it should?