This is one of the most controversial cases for me. Conan letting this attempted murderer go? What? I would be completely uncomfortable with this idea if I was in Conan shoes.
Now it is uncommon for Conan to not get the police involved for attempted murderers if they acted due to a misunderstanding. One example is there's a case where the culprit used a sea snake to poison someone due to some misunderstanding. The victim lived and Conan(as Kogoro) decided not to get the police involved when he did his deduction show. For this case, I will say the wife is a saint for forgiving her husband. I hope the husband learns from this terrible mistake.