All you need is one conclusive piece of evidence proving JBs innocence for everything else to crumble away, Cutie, be it Mugford, the silencer or anything else!
For instance the CT think the Milbank phone call is JBs alibi, and obviously if it is accepted will sweep aside all other evidence against him!
No one needs to prove their innocence either at trial or at any subequent CoA hearing. Often this is simply not possible because there is not any evidence available to prove definitive innocence (or guilt).
At trial the burden of proof is with the prosecution to prove the defendant is guilty 'beyond reasonable doubt'. That's a pretty low bar. In JB's case it was done 10/2 majority.
At any subsequent CoA hearing the burden is with the defence to show 'fresh evidence' which fundamentally alters a
key aspect of the case against JB at trial to the extent that 3 appeal court judges will think ' oh just wow, had jurors heard this at trial I bet they would not have returned the verdicts they did!' And the only key aspect that will have this effect is undermining the blood/silencer.
There was no 999 call. Just the GPO linking the open line at WHF to EP. Those that understand the case know this as it can be evidenced from the physical evidence at soc by way of blood stains, casings, distance of shots, trajectories and wound tracks. NB made the call to JB, NB hears gunshots upstairs (SC opening fire on June prone in bed) NB drops the handset where it was found and runs upstairs where he sustained his facial shots. This can be proven from all the physical evidence captured at soc. There was one phone call from WHF: NB to JB. Claims that NB called EP and someone inside dialled 999 are wrong supported by all the physcial evidence.