Executive Summary: Key Legal and Evidentiary Issues

• Adequacy and timeliness of the Regional Municipality of Halton’s documentary production in advance of discoveries, forming the backdrop for multiple disclosure motions.
• Misuse of generative AI by a self-represented litigant, resulting in non-existent case citations and fabricated legal principles being placed before the court.
• Deliberate failure to verify AI-generated authorities against reliable legal databases, undermining the integrity of the factum and the litigant’s credibility.
• Litigation conduct issues arising from misleading the court twice with fictitious authorities and then minimizing the seriousness of that conduct in subsequent costs submissions.
• Causation of “costs thrown away” due to the adjournment of the motion, requiring Halton’s counsel to investigate, expose, and respond in detail to the flawed authorities.
• Assessment of substantial indemnity costs, including apportionment between work on the misleading factum and broader responding materials, culminating in a lump-sum costs award.

Facts and procedural background

The litigation arises from a civil proceeding brought by the Regional Municipality of Halton against Nicolas Rewa, Marion Rewa, Rewa Consultant Limited and 1103882 Ontario Limited. From the perspective of the available decisions, the dispute reached the Superior Court of Justice in Ontario in the context of motions about the adequacy of Halton’s documentary production prior to examinations for discovery. Three related motions were scheduled to be heard on June 26, 2025; one of these was brought by Mr. Nicolas Rewa, who appeared as a self-represented litigant. The court had reserved two full days for these motions, and they were intended to address disclosure issues and “housekeeping” matters before the case proceeded further. In connection with his disclosure motion, Mr. Rewa filed a factum that purported to rely on various case authorities and legal principles. Those authorities, however, were not drawn from conventional research on platforms such as the Canadian Legal Information Institute (CanLII), but had instead been generated through the use of generative AI. When counsel for Halton reviewed the materials, they discovered that a number of the cited decisions and legal propositions did not exist in the reported jurisprudence. This discovery compelled Halton’s counsel to devote significant time to checking each alleged authority, identifying the precise defects, and preparing detailed responding materials explaining to the court the full extent of the problem. The hearing of June 26, 2025 did not proceed as planned. Mr. Rewa advised the court that he was unwell and could not continue into the following day, which contributed to the need for an adjournment. More importantly, the judge concluded that the motion had to be adjourned because of the serious concerns raised by the non-existent authorities in Mr. Rewa’s factum and the anticipated legal submissions built on that flawed foundation. In an earlier endorsement dated August 1, 2025, the court (RSJ E. Ria Tzimas) found that Mr. Rewa had twice attempted to rely on non-existent legal authorities and that his conduct was deliberately misleading. The August endorsement adjourned his motion and ordered that he pay Halton’s costs “thrown away” on a substantial indemnity basis, while also giving him an opportunity to renew his motion by a specified deadline if it were supported by proper materials.

Conduct relating to AI-generated authorities

A central factual and legal theme in the later costs decision is the court’s treatment of Mr. Rewa’s use of generative AI and his explanation for the resulting errors. At the time of the disclosure motion, Mr. Rewa suggested that, as a self-represented party with limited resources, he did not fully appreciate the shortcomings of relying on AI-generated case law. The court initially accepted that he was not a trained lawyer and might not understand how to evaluate AI-produced authorities; however, this explanation became untenable when contrasted with his subsequent costs submissions. In those costs submissions, filed late but nonetheless accepted by the court, Mr. Rewa displayed a detailed understanding of CanLII as a primary free research tool that is updated daily and offers sophisticated keyword searching, citation tracking and links to legislation. That demonstration of familiarity undercut his earlier claim of limited research capacity. The court inferred that, given his knowledge of proper research methods, he could and should have verified the AI-generated citations against authoritative sources before filing them. The court emphasized that this was the second time Mr. Rewa had advanced non-existent authorities and that he remained unwilling to acknowledge the seriousness of his misconduct. Rather than using his costs submissions to accept responsibility and show contrition, he adopted a minimising tone, treating the episode as “no big deal” and attacking the reasonableness of Halton’s claimed costs. This attitude, in the court’s view, aggravated the concerns about his credibility and respect for the administration of justice.

Adjournment, failure to correct the record, and abandonment of the motion

The adjournment of Mr. Rewa’s motion had several intertwined causes, but the court was clear on what primarily drove the result. While illness can fairly justify a short postponement without costs, the judge stressed that the primary reason for the adjournment was the improper nature of the factum and anticipated submissions based on non-existent authorities. The court rejected Mr. Rewa’s assertion that the matter was adjourned solely because the court “could not reach it” within the scheduled time; in reality, the court had set aside sufficient time, and but for the problems arising from his materials and his claimed inability to proceed, the motion could have been heard. Another aggravating factor was the way Mr. Rewa responded after Halton specifically flagged the problems with his authorities. Halton’s responding factum painstakingly walked through the citations in question, explaining for each why it was inaccurate or fictitious. Rather than promptly advising the court of his error and seeking leave to amend or re-file his materials, Mr. Rewa took no proactive steps to correct the record. The court noted that, had he genuinely misunderstood the limitations of generative AI, he had every opportunity—after being confronted with detailed rebuttal—to alert the court, withdraw or revise the impugned factum, and request a reasonable adjournment to prepare proper submissions. His failure to act in that way reinforced the conclusion that he was not taking his obligation of candour to the court seriously. The August 1, 2025 endorsement nonetheless left the door open: Mr. Rewa was invited to renew his motion by September 30, 2025, supported by corrected materials. He never did so. As a result, by the time of the 2026 costs endorsement, his disclosure motion had effectively been abandoned, leaving Halton with substantial “thrown away” costs incurred in responding to a motion that never proceeded.

Assessment of costs and reasoning on quantum

In its costs submissions, Halton sought approximately $24,590 in costs thrown away as a result of the aborted motion. Those claimed amounts were based on counsel’s time spent reviewing and rebutting the flawed factum, preparing the responding materials, and dealing with overlapping issues connected to the other motions that were scheduled for the same dates. Mr. Rewa countered that figure was grossly disproportionate and argued that an amount in the range of $1,100 would be sufficient, suggesting that the work to identify the non-existent authorities involved little more than a simple CanLII search. The court rejected this characterization as unrealistic. It accepted that Halton’s counsel had undertaken a complex task: discovering that the authorities did not exist, chasing down each citation, identifying the specific defects or misstatements, and then compiling a coherent explanation of those problems for the court. Without those efforts, the true magnitude of the defects in the factum might not have been uncovered. On that basis, the court found that responding to the misleading authorities alone reasonably required about 16–18 hours of work at an average rate of $450 per hour, which on a substantial indemnity scale amounted to roughly $7,000. The bill of costs, however, also included time spent on broader responding materials that went to the substantive disclosure issues raised by Mr. Rewa’s motion. Those efforts were relevant to the concept of “costs thrown away” because the motion was never renewed: if he had proceeded on the strength of revised materials, the original responding submissions could have been reused and would not have been wasted. After reviewing the dockets, the court accepted that senior counsel likely spent approximately 15 hours addressing Mr. Rewa’s disclosure concerns, at an average rate of $630 on a substantial indemnity basis. That portion of the work was valued at about $8,000. The court recognised that some time entries overlapped with work done for the other two motions and with joint “housekeeping” matters. Because Halton’s time records did not neatly separate those tasks, the court applied an implicit discount by not granting the full $24,590 claimed. Instead, it aggregated $7,000 for the response to the flawed factum and $8,000 for the broader disclosure-related work to arrive at a rounded figure of $15,000 as the appropriate amount for costs thrown away.

Outcome and significance

The court ultimately fixed costs against Mr. Rewa in the amount of $15,000, inclusive of disbursements and applicable taxes, payable within 30 days of the February 12, 2026 endorsement. No insurance policy or contractual clauses were discussed in the reasons; the decisions focus entirely on procedural issues—namely disclosure obligations, the proper use of legal research tools, litigant honesty, and the cost consequences of abusing generative AI in a court filing. Substantive merits and any underlying damages claims are not addressed in the available decisions. The Regional Municipality of Halton emerges as the successful party in the costs dispute. The award is expressly framed as compensation for costs “thrown away” because the motion had to be adjourned and was subsequently abandoned, and as a stern reminder that attempting to mislead the court—particularly by twice presenting non-existent authorities and then trivializing that conduct—will attract serious financial consequences. In total, the court ordered that Mr. Rewa pay $15,000 in costs to Halton, and there is no indication in the available materials of any additional monetary awards or damages beyond this costs order.