When I saw PB's pig skin experiment I thought deja vu. I had actually forgotten the last experiment (save the Aga) was on NB's neck in an attempt to demonstrate the silencer was not attached.
Do photos exist of SC's gsw's showing the gunshot residue not impeded by bloodstains? I don't think there's clear evidence what type of wounds they were in terms of hard contact, barrel/silencer held firmly against the skin, or loose contact, barrel/silencer held somewhere between contact and up to 3mm away from the skin. Afaik this was the evidence at trial.
At trial it is all up for grabs. You only need to demonstrate beyond reasonable doubt. Pretty low bar. Different ball game with CoA. If something can be viewed one of two ways the CoA will side with the original verdict as demonstrated by the 2002 hearing.