Handling grouped objects considered unlogical

If I find a graphic object to be deleted and it is within a group, then this is simple:

if (sSearch == "" && sFType == "TXTL") { // --- empty TextLine
  if (object.GroupParent.constructor.name === "Group") {
    object.GroupParent.Delete(); // ungroup
  }
  object.Delete();
}

However, If I want to process the found object further, it must be ungrouped from the group.
The following just ungroupes the first item in the group from the rest.

oGraphic = oGroup.FirstGraphicInGroup;
while (oGraphic.ObjectValid()) {
  oGraphic.GroupParent = 0;
  oGraphic = oGoup.NextGraphicInGroup;
  nObjects += 1;
}

Even replacing oGoup.NextGraphicInGroup by oGraphic.NextGraphicInGroup does not help, because there is no group anymore for this object.
A more sophisticated algorithm is required:

function UnGroup (oGroup) {
var aItems = [], j, k= 0, oGraphic;
  oGraphic = oGroup.FirstGraphicInGroup;
  while (oGraphic.ObjectValid()) {
    aItems[k] = oGraphic;
    oGraphic = oGraphic.NextGraphicInGroup;
    k ++;
  }
  for (j = 0; j < k; j++) {
    aItems[j].GroupParent = 0;
  }
  return k;
}

However, in a process where I need to ungroup the found item for further processing I need to be able to distinguish whether the group is resolved or still exists. To query GroupParent for undefined gives no solution. For an ungrouped object.GroupParent is still a valid object, but properties of the GroupParent are mostly 0. For a grouped object the properties of GroupParent are mostly not 0:

if (KLD_F.IsGroupableObject (oFound) && (oFound.GroupParent.BorderWidth > 0)) {
// Borderwidth: arbitrary property to indicate validity of Group - no other criterion found
  alert ("object is grouped - needs to be ungrouped; For further processing start over");
  KLD_F.UnGroup (oFound.GroupParent);    // ungroup the items
  KLD_F.oLstObjFound.object = undefined; // start over
}

Do you have a different experience?