Re: "now faces up to 35 years behind bars"
Let's think this through from a few points of view in court.
From a witness first. You know that your evidence can lead to someone's death. You're aware that sometimes there are miscarriages of justice. Can you live, long term, with the possibility that you might have made a mistake and killed someone. From personal experience I can tell you that if you're conscientious the stress of life in the witness box over the years becomes unbearable without that additional thought. Would you want to be there? If you do then you should be automatically disqualified.
Now look at it as a juror. In the 12 men and women good and true there's a good chance that you'll find one who, as a matter of conscience, would not be prepared to vote to take away someone's life no matter how strong the evidence. There's a real likelihood that your hang 'em high approach might lead to he guilty getting off. Hmm.
Now look at it from the jurist's PoV. You're seeing the strongest possible cases failing. Should you accept majority verdicts? For a capital offence? Again, you're aware that miscarriages of justice happen. Maybe, despite all the problems you should require unanimous verdicts. But if you require unanimous verdicts for some cases why do you accept majority verdicts in other cases? After all, and no matter how many failures there are, it's a principle of English law and its derivatives that it's better that the guilty go free than that one innocent man is convicted.
But, hey, it's a lot easier when we can settle complex matters of conscience and justice on the basis of simple economics.