In the Country A legal system, a defendant is presumed innocent until proven guilty. Consider a null hypothesis,

Remember that Type I error occurs when in the process of hypothesis testing, a correct null hypothesis is falsely rejected. That is the procedures used leads to an event that the null hypothesis is rejected, while in reality it should not be rejected. In a jury, the defendent is always presumed innocent until proven guilty. 
Type I error is commited if the jury convicts the defendant despite the fact that the defendent is innocent and type II error is commited if the defendent is declared innocent when in reality he/she commited the crime. Type I error in this case harms the defendant while Type II harms the accuser.