The jury that three years ago convicted Nancy Kissel of murdering her banker husband did so after receiving contradictory and confusing instructions about the cornerstone of her defence, her counsel said yesterday. Gerard McCoy SC told the Court of Appeal that trial judge Mr Justice Michael Lunn had confused the elements of her main defence: that she bludgeoned her husband to death in self-defence while he was attacking her with a baseball bat and trying to sodomise her. The body of Kissel's husband, Robert, a senior manager at investment bank Merrill Lynch, was found on November 6, 2003, wrapped in a carpet in a recently hired storeroom below the couple's flat in Parkview, Tai Tam. He had been killed four days earlier. Mr McCoy told the court that Mr Justice Lunn had erred when he told the jury that it needed to consider whether a normal person would consider reasonable the force used by Kissel when she was supposedly defending herself. That was applying an objective test to an entirely subjective situation, Mr McCoy said. The question was what was going on in Kissel's mind when she struck the fatal blows and whether she considered that level of force necessary given the perceived threat. She had told the court that her husband had been saying, 'I'm going to f***ing kill you ... you f***ing bitch', just before she struck him on the head with a lead ornament. Mr McCoy said that the judge had instructed the jury they could not consider the accused had acted in self-defence if her actions were retaliatory or in revenge. But when he also offered them a defence of provocation, which was in essence retaliatory, he had muddled the question. 'With the greatest respect to the judge,' Mr McCoy said, 'if I can draw an analogy to a computer: if you put rubbish in, you get rubbish out.' He said the way in which the judge had delivered his instructions was equivalent to telling the jury that they were not allowed to consider the merits of Kissel's stated case. If court vice-president Mr Justice Michael Stuart-Moore, Justice of Appeal Mr Justice Frank Stock and Mr Justice Alan Wright agreed with him, they had to allow the appeal and consider a retrial, he said. Kissel looked on with approval, and an occasional nod to her mother sitting nearby. Earlier, she had muttered her disagreement as acting Deputy Director of Public Prosecutions Kevin Zervos SC denied that the instructions had been confusing. The case continues.