5In Potts [2012] the appeal against conviction failed because:the difference of opinion between the medical experts meant there were grounds for the jury to not accept there was a causal link between the appellant's behaviour and his mental conditionthe trial judge failed to direct the jury that they should make a value judgment and not just rely on medical opinionsthe appellant had not described hearing voices until giving evidence in the trialit was not proved that the appellant suffered from paranoid schizophrenia

The appeal against conviction in Potts [2012] failed due to several reasons:

1. There was a difference of opinion between the medical experts. This discrepancy provided grounds for the jury to question and potentially reject the causal link between the appellant's behavior and his mental condition.

2. The trial judge did not instruct the jury to make a value judgment. Instead, they were led to rely solely on medical opinions.

3. The appellant did not mention hearing voices until he was giving evidence in the trial. This could have raised doubts about the credibility of his claims.

4. It was not conclusively proven that the appellant suffered from paranoid schizophrenia. Without definitive proof, the jury may have found it difficult to accept this as a factor in the appellant's behavior.