I'm a bit hazy about this but wasn't the law changed some time in the 1990s so that a court could consider silence or "no comment" as, if not a presumption of guilt, at least no longer a presumption of innocence. Until then the law held that the prosecution had to prove its case and if the defendant remained silent or just answered no comment, the jury were not allowed to draw any inference from it, but this changed, so that the jury could draw its own conclusion from the defendant's refusal to answer. I seem to remember this because there was a big "human rights" outcry about this change of law at the time. Does anyone know more about this?