What is the test for a trial judge to admit fresh evidence?

Alberta v. B.M. details a more explicit rejection of a trial judge having a general residual authority to admit fresh evidence despite that evidence not meeting the four part test requirements. A failure to meet due diligence standards is fatal (para. 12). In civil matters such as this one, the new evidence must effectively determine and change the outcome (paras. 12, 13). A party can never take one position at trial, and then advance a different scenario based on new facts following the decision, unless that party can demonstrate the necessary due diligence standard was met and that the inconsistent positions were an unavoidable consequence of the manner in which evidence became available (para. 90).