In reply to andrewmcleod:
> The argument is that your thumb is too weak to override the cam if someone falls off. I wonder if she is too light for this to be totally true though...
That's really interesting. Perhaps her Dad's thumb is too strong :^)
> As soon as you feel rope zipping through your hand it is probably already too late, and any attempt to grab the dead rope may just result in you burning your hand rapidly (which is not conducive to you holding on).
Well all you have to do is take your thumb off the cam, even just let go completely, and the device will lock, so their shouldn't be any danger of rope burn, unlike a non-autolocking plate. Sounds like her Dad didn't react in time. Maybe tired and/or got distracted by something?