Complex sentence: His Lordship explained that the rationale for the section 15 presumption was the difficulty in proving the purpose of trafficking; in such cases dealing with drug trafficking, the strongest attainable evidence was likely to be the act of transporting the drugs.
Split into simpler sentences: His Lordship explained that the rationale for the section 15 presumption was the difficulty in proving the purpose of trafficking. In drug trafficking cases, the strongest attainable evidence was likely to be the act of transporting the drugs.