"Photographs were taken prior to the silencer entering the chamber and this along with documentary evidence should show whether or not the ends were taped. However the heat and humidity from the chamber is likely to be more damaging to the blood flake than the superglue fumes."
You know that these pictures still exist? What documentary evidence? If the ends were taped it's game over for the theory and even if they weren't it doesn't mean that the blood flake would be damaged given that it was inside. You would have to run this test many times but that still wouldn't prove that 30 years ago blood was planted inside the silencer.
No I don't know if the photos and documents exist. They should but then so should the exhibits that were destroyed. Either way I don't see it as being that relevant. The manufacturers and the research centre at Sandridge should be able to confirm what the processes and procedures were at the time. If they are not then the courts are likely to rule favourable terms in JB's favour as outlined above.
Why is it game over if the ends were taped? The chamber was potentially harmful by way of heat, humidity and the fumes. Forensic analysis of the silencer testing for superglue residues will probably confirm one way or the other.
If the tests are run as I have outlined above and one or more of the blood groups are consistently negative this will show the flake was unable to sustain the environment in the chamber and/or the ambient temp before and after. The prosecution claim one silencer. A silencer that contained a flake of blood as a result of drawback/SC's contact wound. If it is put through the same environment as the flake and unable to deliver the test results its game over for the flake.
The tests need to match the scenario from the claimed drawback to blood analysis of the flake at the lab as closely as possible including time kept at ambient temperature before and after the fuming chamber.
I wouldn't describe it as a theory more a hypothesis at this stage.
In fact when I first contacted the forensic service provider around the beginning of February it was based on heat from the rifle being fired, hot gasses in the silencer, size of flake and time kept at ambient temperature.
We could speculate about many things but until the tests are carried out it remains simply a hypothesis which I'm cautiously optimistic about.
Don't forget bacteria!