The 'train of inquiry' test from Peruvian Guano has no application to discovery under NSW Supreme Court Rules Pt 23 r 3(3)(a). Relevance for discovery is determined solely by the definition in r 1(d): whether a document could rationally affect the assessment of the probability of the existence of a fact in issue. Trial judges should apply the rules in accordance with their own terms and avoid citing formulations from different rule regimes.
The full text is available to signed-in members, including the 8 later cases that cite this judgment.
1 of the 8 citing cases carry a classified treatment. How each court treated it is available to signed-in members.