The only thing I do not understand about the liablility issue is "Why has that not been an issue for Dave?".
I am always kind of skeptical but I have to think the greater profit in selling the whole breech plug/ ventliner combo played a big part in their decision to braze them together.
Muzzleloading is inherently dangerous if you are not careful, I don't see where the vent liners really make it more so.
Art