Executive Summary: Key Legal and Evidentiary Issues

• Appeal arises from a case management decision involving a long-standing trust dispute between the Piikani Nation and multiple parties tied to the Oldman River Dam agreement

• Ms. Kostic was denied permission to strike portions of an amended statement of claim found to be authorized by earlier court orders

• Summary dismissal of claims against Ms. Kostic was refused as her proposed affidavit failed to demonstrate the claims lacked merit

• The Case Management Justice denied "immediate save harmless relief," deferring indemnity and defence cost issues to the upcoming trial

• Discretionary decisions of case management justices attract a high degree of deference and will only be overturned upon an error of principle or clear unreasonableness

• All grounds of appeal were dismissed, with unresolved issues directed to the trial scheduled for 2027

The origins of the dispute

This case stems from a trust established in 2002 under an agreement between the Piikani Nation and the Provincial and Federal Governments, which allowed land to be used for the Oldman River Dam. Litigation surrounding that trust began in 2006 and has since generated a proliferation of related actions. The appellant, Liliana Kostic, is one of several parties entangled in these proceedings, alongside Raymond James Ltd., Janet Potts, CIBC World Markets Inc., CIBC Trust Corporation, and the Piikani Nation. The present appeal, heard by the Court of Appeal of Alberta, challenges specific portions of a case management decision issued by Justice M.A. Marion on August 26, 2025 (reported at 2025 ABKB 493), involving four separate actions identified by abbreviated case numbers 0601, 0801, 1601, and 1701.

Ms. Kostic's applications before the case management justice

Ms. Kostic had sought a series of orders from the Case Management Justice (CMJ), including permission to file an application to strike portions of an amended statement of claim in action 0601, permission to file a notice to co-defendant against Raymond James, permission to file an application for summary dismissal of action 0601, permission to amend her originating application in action 1601 to seek "immediate save harmless relief" and aggravated and punitive damages against CIBC, permission to amend an action known as Kostic-CIBC Trust Action #2, and permission to seek further particulars and discovery. Of these, items (a) and (c) were dismissed outright, item (d) was partially dismissed (the aggravated and punitive damages amendment was allowed, but the "immediate save harmless relief" was not), while items (b), (e), and (f) were granted with some caveats and directions from the Case Management Justice.

The striking application and issue estoppel

Regarding the application to strike portions of the amended statement of claim, the CMJ found that the impugned paragraphs were authorized by earlier orders. Attempting to strike them at this stage constituted both a collateral attack on the order permitting them and would be barred by issue estoppel. The CMJ compared the impugned paragraphs with the prior orders and found that the amended statement of claim was precisely in the form approved. The Court of Appeal found no reviewable error in these findings.

Summary dismissal deemed impractical

On the question of summary dismissal, the CMJ found that the application was not barred by res judicata or issue estoppel but concluded that Ms. Kostic had not met the test for dismissal. Her proposed affidavit did not show that many of the claims against her had no merit, and the determination of those claims gave rise to issues requiring trial. The CMJ further noted that some of the arguments advanced by the appellant could not be reasonably or fairly resolved summarily. He reasonably anticipated a "mammoth" amount of documentation to be filed in support of a summary dismissal action, as well as further pre-application disputes, and concluded it would be easier and more expedient to have the matter set for trial. The Court of Appeal found no reviewable error in these conclusions.

The indemnity and save harmless relief question

The most substantive ground of appeal concerned Ms. Kostic's request for "immediate save harmless relief" against CIBC. The Court of Appeal noted it had repeatedly addressed Ms. Kostic's claim for defence costs and indemnity from Raymond James and/or CIBC entities in prior decisions, confirming that this is a matter that must be determined at the trial of the 0601 action rather than in advance. The CMJ properly concluded that he was bound by those decisions. While the Court acknowledged that new information had arisen since the initial decision, the core concern articulated in prior decisions, including those reported at Kostic v CIBC Trust Corporation, 2018 ABCA 355 (leave to the Supreme Court of Canada denied at 2019 CanLII 37469), and subsequently affirmed in related decisions at Kostic v CIBC Trust, 2019 ABCA 29 and Raymond James Ltd v Kostic, 2025 ABCA 296, remained. There are significant factual issues that can only be determined in the context of a full evidentiary record. Allegations arising regarding the conduct of CIBC in a prior appeal on this issue remain disputed and cannot be resolved on the limited record available at this time. The threshold required to re-open or reargue an appeal is a high one, and it was not met in this case.

The ruling and outcome

The Court of Appeal of Alberta, composed of Justices Slatter, Antonio, and Hawkes, dismissed the appeal on April 27, 2026, finding no reviewable error in the CMJ's decision across all three challenged grounds. The respondents — Raymond James Ltd., Janet Potts, CIBC World Markets Inc., CIBC Trust Corporation, and the Piikani Nation — prevailed. The appellant raised alleged "misrepresentations" and other errors in submissions to the Court and the case management judges; however, the Court noted that none of these other matters were the subject of this appeal and they were not expressly dealt with by the CMJ. These issues can, if necessary, be dealt with at the trial in 2027. No specific monetary award was ordered, as the decision concerned procedural and case management matters rather than a determination on the merits.