The slip rule has been subject to repeated misunderstanding, Maria Kell observes its revival
The substance of the slip rule—more prosaically known as CPR 40.12—is simple enough on first reading: “The Court may at any time correct an accidental slip or omission in the judgment or order”.
The commentary in the White Book, however, is more ominous, with the claim that it is “one of the most widely known but misunderstood rules”. There is room for subjectivity and debate in determining the key issues, namely what is an accidental slip and what, by contrast, is a substantive error.
Mr Justice Eder recently gave a robust judgment, in the matter of Riva Bella SA v Tamsen Yachts GmbH [2011] EWHC 2338 (Comm), [2011] All ER (D) 41 (Sep), in which he chose to exercise his discretion in order to meet the interests of justice and accepted an application to amend an order under the slip rule. In doing so, he distinguished the previous authority on this issue—Leo Pharma A/S and another v Sandoz Ltd
