Legal practitioners involved in contested court proceedings are familiar of the various difficulties which may arise in court proceedings, particularly in relation to costs. Due to the human nature, inevitably mistakes may occur on court documents, which may unintentionally prejudice a party. Legal practitioners are familiar with “the slip rule” which allow such accidental clerical mistakes may be corrected by the Court.
Broadly speaking, the slip rule allows a party to request the court to correct a clerical mistake, error or mission arising from an accidental slip on a court order or judgment, so that the order truly represents what the court pronounced or intended to pronounce. However, it is a power to be “exercised sparingly [by the Court], lest it encourage carelessness by a party’s legal representatives and expose to risk the public interest in finality of litigation” see Achurch v The Queen  HCA 10 at  per French CJ, Crennan, Kiefel and Bell JJ quoting Gould v Vaggelas (1985) 157 CLR 215 at 275.
Practitioners who become aware of any clerical errors or accidental slips/omissions in court orders and judgments must move expediently to have those matters corrected. Any delay may result in a lost opportunity and bar parties from correcting potentially mistakes, particularly in cases where the error is not plain on its face. This was recently confirmed by Chief Justice French in the High Court in the cases of Certain Lloyd’s Underwriters Subscribing to Contract No IH00AAQS v Cross & Thelander & Thelander  HCA 52.
In a judgment given on 12 December 2012, the High Court allowed an appeal by the insurer against the NSW Court of Appeal’s decision in a personal injury matter. Prior to hearing the appeal, the Court granted the insurer special leave to appeal provided it give an undertaking to pay the respondents’ costs of the application and appeal. Subsequently after hearing the appeal, the Court (among other things) ordered that the orders of the Court of Appeal about the legal costs incurred in the NSW District Court be dismissed. However, the High Court did not expressly make any order in relation to the costs of the NSW Court of Appeal proceedings.
The insurer subsequently applied on 6 December 2015 to the Court to amend the 2012 judgment pursuant the slip rule enunciated in Order 3.01.2 of the High Court Rules 2004 to clarify an apparent omission to deal with the costs of the NSW Court of Appeal proceedings. Chief Justice French accepted the insurer’s submission that the principle that the costs of a successful party should be paid by the unsuccessful party should not have been disturbed in relation to the costs of the proceedings in the Court of Appeal but also noted that in “test cases” it “is not unusual to find special leave to appeal granted on the basis that the applicant will not seek to disturb the orders as to costs already made in the court appealed from, or orders made to that effect”.
His Honour held that while it would have been appropriate for the insurer to move promptly to correct the allegedly erroneous failure to set aside the NSW Court of Appeal costs, the long history of the complex litigation was not a sufficient excuse to explain delay seeking the correction. It was noted that “the absence of an order setting aside the costs orders in the Court of Appeal cannot be judged, at this remove in time, as an error of the kind [to be corrected under the slip rule].”
Ultimately, the Court dismissed the application such that the insurers were required to pay the respondents both the costs of the appeal to the High Court and the costs of the NSW Court of Appeal proceedings.