There again, it depends on time frame. At some point in 1863 the Confederate government established medical review boards in each Congressional district. A man who wanted a medical discharge had to be examined by the board and receive a signed certificate stating their opinion. If I understand, they could designate that the man was available for light duty only (such as Quartermaster Bureau), or was completely unfit for any military duty.

Due to conditions in Mississippi during the second half of the year, medical examining boards may not have been able to meet. Capt English may have believed that furnishing a substitute would be a better option. Of course at the end of 1863 Congress removed the ability to opt out of military service, making both the substitute and his principal (the man who provided the substitute) available for the draft.

After the war ended, would the widow have had a legal option to hold anyone liable for actions imposed by the Confederate government? I wouldn't think so.