Looking at subsequent case law, it appears the second option would have had a greater chance of prevailing than the first. (mjdr-rrdm.ca)
This has been heavily innovated on by subsequent case law, most notably the House of Lords decisions in [2000] UKHL 54; [2001] 1 AC 596, and < Miller and Macfarlane > [2006] UKHL 24; [2006] 2 AC 618. (morton-fraser.com)
Subsequent case law indicates that defence lawyers should examine unused material (see R v Adams [2007] EWCA Crim 1, [2007] All ER (D) 25 (Jan)-RRB-. (newlawjournal.co.uk)