First, as a husband, Liang Wenchao will not report his wife from an emotional point of view. But as a prosecutor, he is bound to practice justice.
Where does the movie fall short? It makes sense for him, as a husband, to go and take the perjury on himself. But as a prosecutor he was not motivated enough to confess to his superiors. In standing up to his superiors, though, one could make the reasonable assumption that it wasn't the wife who wanted to use the technique to keep Leung alive, but rather that Leung wanted to stay alive and so committed perjury.
The law will not let a bad person off the hook, nor will it wrongly convict a good person. So the real murderer will inevitably be put in jail, but there is no reason for the real murderer to turn himself in voluntarily since he is off the hook.
So, in the second half of the movie, Liang Wenchao used the "human brain copying technology" to transfer his consciousness to the murderer, and used the body of the criminal to confess everything to the court. Although Liang Wenchao was faced with a dilemma, he always defended his wife and stood up for justice.
Let's talk about the wife played by Zhang Junning again. When the wife learns that there is such a technology that can save her husband, she uses her position to perjure herself in order to obtain such a technology, so that the real murderer can be exonerated.
When breaking the law can save your life, do you choose to obey the law, or do you choose to save your lover? The movie discusses the wife's choice under such extreme conditions. With no money, no advanced medical skills, but wanting to save the life of her loved one, when a life-saving technology happens to be in front of her, she is doomed to make a choice, and also doomed to the consequences and doomed end of making such a choice.
The movie ends with the wife finally turning herself in. First of all, let's not forget that it was Liang Wenchao's wife who actually committed perjury, and secondly, the law will not spare a bad guy, nor will it wrongly accuse a good guy. Therefore, even if the wife is exempted from punishment, she must still turn herself in in order to be legally justified. Secondly, it is the criminal who is locked up in the prison, but it is actually Liang Wenchao, so it is reasonable for the wife to turn herself in to her husband.
And the setting at the end of the movie can be a highlight. Not only does it allow justice to be done, and the disease can be removed from Liang Wenchao, who was transplanted in the body of the criminal, but it also allows two people who love each other to stay together, with both love and law. Although, the only misfortune is that the two have to spend the rest of their lives in prison, but both from the legal and emotional point of view is the best arrangement for the two.