Tobin v Minister for Defence

Factual and Procedural Background

The Plaintiff, formerly employed as an aircraft mechanic at The Aerodrome from 1990 to 1999, alleges that exposure to hazardous chemicals and involvement in a practice known as “tubbing” caused him personal injury. In January 2014 he issued personal-injury proceedings against the Defendants (collectively “the State”) for negligence, nuisance, breach of duty, breach of statutory duty and breach of contract.

After the Plaintiff supplied particulars in March 2014, the Defendants filed a defence in June 2015 putting the Plaintiff on strict proof of every allegation save for the fact of employment. The Plaintiff then sought discovery of 15 categories of documents. A motion for discovery issued in October 2015 when voluntary discovery was refused.

High Court (October 2016, Judge McDermott) granted broad discovery, rejecting the State’s proportionality objections. The Court of Appeal (July 2018, Judge Hogan, with Judges Peart and Irvine concurring) substantially narrowed that order, directing the Plaintiff first to use interrogatories and limiting discovery to the Engine Repair Flight workshop (“ERF”).

The Supreme Court granted leave because the appeal raised a question of general public importance: how courts should balance discovery obligations against disproportionate burdens in modern litigation. The present judgment resolves that appeal.

Legal Issues Presented

1. Whether the burden associated with full discovery justified limiting discovery and requiring the Plaintiff to resort to interrogatories first.
2. Whether discovery should be confined to documents concerned solely with exposures occurring physically inside the ERF, or should extend to the entire period during which the Plaintiff was assigned to the ERF throughout The Aerodrome.
3. Which party bears the onus of proving that discovery of relevant documents is or is not “necessary” under Order 31, rule 12 of the Rules of the Superior Courts when proportionality is in dispute.

Arguments of the Parties

Plaintiff's Arguments

• The requested documents are indispensable for expert evidence on chemical exposure, causation and safety training; interrogatories cannot elicit unknown chemicals.
• The Defendants’ blanket denial of all allegations widened the issues and thereby increased discovery needs; they should not benefit from that stance.
• Limiting discovery to the ERF ignores pleadings that reference exposures elsewhere while assigned to the ERF.
• The State’s claimed burden (220 staff-hours) is moderate when compared with complex commercial litigation and does not warrant curtailing discovery.

Defendants' Arguments

• Full discovery would impose a disproportionate logistical and financial burden; interrogatories can supply the same information more efficiently.
• The pleadings confine the claim to exposures physically inside the ERF; therefore discovery should be similarly confined.
• Under the principle that discovery is unnecessary where information is otherwise available, interrogatories (and notices to admit) are fundamental alternatives.
• The Plaintiff already listed chemicals in his replies to particulars; he should frame interrogatories about those chemicals rather than seeking wide-ranging discovery.

Table of Precedents Cited

Court's Reasoning and Analysis

Judge Clarke (for a unanimous Supreme Court) began by reaffirming that relevance and necessity are the primary criteria for discovery. Necessity, however, now incorporates proportionality and the availability of cheaper alternative procedures.

The Court set out a structured approach:

1. Once the requesting party shows relevance, necessity is prima facie satisfied.
2. The burden then shifts to the resisting party to demonstrate, with evidence and argument, that discovery is not necessary because (a) it is disproportionately burdensome, or (b) alternative procedures (e.g., interrogatories) can achieve the same end at significantly lower cost.
3. In evaluating proportionality, courts must consider (i) scale of the burden, (ii) likely evidential value of the documents, (iii) availability and effectiveness of alternatives, and (iv) whether pleadings unnecessarily expand issues.

Applying those principles:

• Scope of Claim: Pleadings covered exposures during the Plaintiff’s ERF assignment throughout The Aerodrome, not merely exposures physically inside the ERF. The Court of Appeal erred in restricting discovery geographically.
• Burdensome Nature: The State estimated 220 staff-hours for discovery. The Supreme Court characterised this as a “moderate” rather than severe burden, far below large commercial cases.
• Effectiveness of Interrogatories: Interrogatories would still require the State to research archival records to answer meaningfully. Hence, they would not materially reduce cost yet would deprive the Plaintiff of underlying documents essential for expert analysis.
• Proportionality Balance: Given the centrality of chemical-exposure evidence and the moderate burden, full discovery (subject to the temporal limitation) was proportionate.
• Special Status of the State: The Court rejected any suggestion that the State’s resources alter the proportionality test; taxpayers merit the same protection as private litigants.

Accordingly, the Court reinstated the High Court’s discovery order for Categories 1 and 12 (with a shortened temporal span) and reversed the Court of Appeal’s substitution of interrogatories for discovery in Categories 2, 5, 6, 10, 11 and 13.

Holding and Implications

HELD: The appeal is allowed. Save for limiting certain categories to the period 1 January 1990 – 28 February 1994, the High Court’s order for discovery is reinstated.

Implications: The judgment clarifies the Irish proportionality framework in discovery, shifts the onus to the resisting party once relevance is established, and outlines when alternative procedures can displace discovery. While providing guidance of general application, it does not alter the legal test but refines its practical deployment in modern, potentially burdensome discovery scenarios.