Defendant’s Wrongdoing as Countervailing Factor in Delay Applications

Introduction

Mullen v O'Brien & Anor ([2025] IEHC 302) is a High Court decision delivered by Mr Justice Barry O’Donnell on May 28, 2025. The plaintiff, Karl Mullen, sued the first defendant, retired Garda and scout leader Tim O’Brien, for numerous torts including assault, battery, trespass to the person and sexual assault, and sued scouting Ireland Services for breach of duty and negligence. Six years after issuing proceedings in February 2018, the first defendant moved to strike out the action for want of prosecution under the Primor test, or alternatively to try a preliminary issue whether the claims were statute-barred. The plaintiff counter-moved to compel replies to a notice for particulars. Central issues included (1) the application of delay-based strike-out doctrines (Primor for post-commencement delay; O’Domhnaill for pre-commencement delay), (2) whether a claimant’s disability—allegedly caused by the defendant’s own wrongdoing—can justify late commencement, and (3) the propriety of a stand-alone preliminary trial on limitation grounds.

Summary of the Judgment

The Court refused to strike out for post-commencement delay. It found:

• Up to May 2020 the plaintiff prosecuted his claim with reasonable expedition; subsequent slippage between April 2021 and October 2023 was inordinate and inexcusable, but not sufficient to deprive the defendant of a fair hearing under the Primor balance-of-justice test.
• Pre-commencement delay caused by the plaintiff’s continuing psychological disability—alleged to stem from the defendant’s own sexual assaults—constituted a “countervailing factor” under O’Domhnaill and Beatty v Beatty. The defendant could not use that delay to bar the claim entirely.
• The application for a preliminary trial on the statute of limitations was inappropriate: no agreed facts could be assumed, and fairness demanded the limitation issue await the full trial.
• The plaintiff’s motion to compel particulars was granted; the first defendant must deliver his replies in short order.

Analysis

Precedents Cited

• Primor Plc v Stokes Kennedy Crowley [1996] 2 IR 459: Established the three-stage test for post-commencement delay—whether delay is inordinate, inexcusable, and whether the balance of justice disfavors continuation.
• O’Domhnaill v Merrick [1984] IR 151: Recognition that excessive pre-commencement delay can defeat a claim, but that countervailing circumstances—such as defendant conduct—may bar reliance on it.
• Nash v DPP [2015] IESC 32: Constitutional imperative that disputes be resolved on their merits unless exceptional prejudice arises.
• Padden v McDarby [2024] IECA 207: Clarified that harmless limitation periods do not translate into culpable delay, but pre-commencement delay can inform whether post-commencement delay is excusable.
• Cave Projects Ltd v Gilhooly [2022] IECA 245: Emphasized defendants share responsibility to drive litigation forward.
• Beatty v Beatty [2025] IECA 64: Held that delay caused by defendant’s own wrongdoing (e.g. grooming or abuse) must be treated as a countervailing factor under O’Domhnaill and not deployed to strike out a claim.
• IBRC v Fingleton [2024] IESC 59: Confirmed that to dismiss an action for pre-commencement delay, a defendant must prove a fair trial is no longer possible.

Legal Reasoning

The Court conducted a two-stage analysis. First, it applied the Primor criteria to post-commencement delays:

1. Inordinate delay: From issuance in February 2018 to May 2020, Mullen advanced his claim diligently (pleadings, replies to particulars). From April 2021 to October 2023 there was a near-total lapse, which was inordinate.
2. Inexcusable delay: No satisfactory explanation for the prolonged lull—principally due to the plaintiff’s pursuit of discovery—below the standard required.
3. Balance of justice: The test focuses on prejudice caused by plaintiff delay. Although witness memory may fade and the defendant’s wife died in 2021, such prejudices either were contributed to by the defendant’s own dilatoriness or could not realistically have been avoided even with swifter conduct. Hence the balance favored trial on the merits.

Second, on pre-commencement delay the Court applied O’Domhnaill in light of Beatty: where the defendant’s alleged abuse caused the plaintiff’s inability to sue until April 2017, that disability must be factored in as a countervailing circumstance. The first defendant could not rely on plaintiff delay when that delay derived from the defendant’s own tortious acts. Further, without agreed facts or affidavit evidence from the plaintiff personally, a stand-alone limitation trial would unfairly constrain his case.

Impact

• Clarifies that where a claimant’s delay in issuing proceedings stems from a disability caused by the defendant’s own wrongdoing—particularly in sexual abuse cases—it cannot be weaponized by the defendant to extinguish the claim.
• Reaffirms the high threshold for striking out: moderate prejudice does not suffice under Primor if fairness to the plaintiff remains.
• Restricts preliminary trials on limitation issues to cases with clearly agreed facts or mutual evidential waivers; otherwise limitation must await full trial.
• Encourages litigants—especially defendants—to use the case-management toolbox (discovery, notices for particulars, interim directions) rather than rely on draconian dismissal applications for delay.

Complex Concepts Simplified

• Primor test: A three-part hurdle for dismissing cases due to slow prosecution: (1) Was delay excessive? (2) Was it without excuse? (3) Does the overall fairness tip against trial? Even substantial delay may not prevail if the defendant can still get a fair hearing.
• O’Domhnaill principle: Pre-commencement delay can bar a suit, but courts will not allow a defendant to profit from delay that the defendant’s own wrongful conduct caused.
• Countervailing circumstances: Any factor—such as defendant misconduct or the plaintiff’s disability—that offsets the injustice of delayed proceedings.
• Preliminary issue trial: A stand-alone mini-trial to decide one legal question upfront. It requires agreed facts or the moving party must adopt the opponent’s pleaded facts.

Conclusion

The High Court in Mullen v O’Brien & Anor has solidified the rule that a defendant cannot shelter behind delay which the defendant’s own wrongdoing produced. The decision underscores the preference for full trials on the merits, reserving dismissal for truly exceptional cases where prejudice attendant on delay makes a fair hearing impossible. Moreover, the judgment limits preliminary trials on limitations grounds to scenarios with clear evidential consensus. Practitioners should note the reinforced duties on both sides to actively manage litigation and the courts’ readiness to safeguard access to justice when detriment arises from defendant misconduct.