If it was on the gun, yes, he is definitely guilty but is it wasn't - that doesn't mean he's innocent.
But if it was not it would mean the evidence was introduced to put it kindly and therefore in the eyes of the law it would be an MOJ . And why was it introduced ? Because there was insufficient evidence to convict.
It actually I think have been very difficult for Bamber if the silencer evidence had not been there because of Julies evidence. I think he would have been found innocent but there would have been a doubt hanging over the case and then a subsequent fight over the estate /land and the family who no doubt still would have told the world that the jury were wrong. But it would have died down for a while.
As much as I would not want a guilty man walking free, I am afraid that I feel we have one of the best justice systems in the world , but it should stand on its merits and rely on a great police force with the highest morals . I find that in general, framing for the noble cause, leaves a very nasty taste in the mouth as far as I am concerned.