In reply to FedUp:
> Similar mechanics with regard to daisy chain failure
It reminded me of exactly that as well. Metolius came up with a simple and elegant improvement on the daisy chain idea to stop it happening:
http://www.metoliusclimbing.com/pas_personal_anchor_system.html
Hopefully someone can do the same with this issue.
I don't think I have any open loop draws amongst mine anymore - even my longish ones - 25 cm DMM ones are sewn through, although I have used the a lot in the past.
It is perhaps is another good argument for having a separate sets of tapes for sport climbing. If I place a nut, I invariably give it another tug once the QD is on - and that might well reveal this problem, but with sport climbing you just clip the QD into the bolt, clip the rope in and off you go...
Get well soon to the unfortunate climber concerned!