The binding legal principles established are: (1) For intervention in an appeal, a party must demonstrate a direct and substantial legal interest in the subject matter of the appeal itself, not merely an indirect interest in its outcome. An interest in the broader commercial implications does not constitute a legal interest in whether a rescission application should succeed. (2) Where a party seeks to rely on a ground for rescission, that ground must be raised in the founding affidavit of the rescission application. A ground raised only in a replying affidavit that was properly excluded cannot form the basis of an appeal. (3) Following Lodhi, a default judgment that is procedurally properly obtained (where the plaintiff is entitled to judgment in the absence of the defendant) cannot be rescinded under Rule 42(1)(a) as erroneously granted merely because a defense on the merits is subsequently disclosed. (4) Courts retain discretion to exclude affidavits filed late without proper condonation applications, particularly where they prejudice the opposing party by raising entirely new matters.