The British offered freedom and even a monetary reward for slaves escaping to the British side, unless the slaves had belonged to people still loyal to the crown, in which case they would be returned. After all, it was royal decree that slaves be used. Before all that, the Georgia colony was a military buffer between the British colonies to the north and Spanish held Florida. General Oglethorpe refused to allow slaves to be used because it was a tactical risk, but the crown issued a royal decree that slaves were to be used in the Georgia colony because they wanted the money from cotton. If anyone was pro-slavery, it was the British. They should demand reparations from the Queen. I'm sure she could use a good laugh.