Should John Mann Be Responsible for What He Had Done?

On September 28, 2016 we had our first in class debate on State v Mann on the issue of slavery. This case was based on a slave named Lydia who was brutally beaten by her owner John Mann. Mr. Mann is saying that he has the right to do what he did because Lydia should obey her master since she is owned by Mr. Mann. The state is saying that this isn't the case, that even though slavery is legal, slaves are still property. It is wrong to damage property, and what Mr. Mann did was simple battery and assault which is against the law. Throughout the course of the class we debated many different aspects of each side, and in the end slavery ended up winning which in my opinion isn't right. Although I had to accept this outcome, it still makes me mad because I feel the state had a stronger argument. Mr. Mann assaulted Lydia and should pay for what he had done.