What is the test for error in an appeal of a motion to dismiss an action for want of prosecution?

We reiterated that an appeal is a review for error, not a trial de novo: H.L. v. Canada (Attorney General), 2005 SCC 25, [2005] 1 S.C.R. 401. In an appeal of this nature (i.e., from the discretionary exercise by a chambers judge of a power), the appeal court is asked to determine whether the chambers judge properly exercised the power at his or her disposal. Here, we must bear in mind that because the power to dismiss an action for want of prosecution is discretionary it falls to be exercised as the chambers judge thought fit, having regard for such criteria as bear upon the proper exercise of that power. In other words, the discretion is that of the chambers judge and we may only ask whether the judge erred in principle, disregarded a material fact, or failed to act judicially in his exercise of that power. We may, of course, also look to see whether the result is so plainly wrong as to amount to an injustice. (Rimmer v. Adshead, 2002 SKCA 12, [2002] 4 W.W.R. 119)