After some experiments I ended with next solution:
var backView = $scope.$viewHistory.views[$scope.$viewHistory.backView.backViewId];
$scope.$viewHistory.forcedNav = {
viewId: backView.viewId,
navAction: 'moveBack',
navDirection: 'back'
};
backView && backView.go();
It looks bad for me, but successfully resolves the problem. I hope this will help to someone.
Update: Now you could actually call
$ionicHistory.goBack(-2);
which is described in ionic's documentation.