public ExecuteModeType ExecuteMode {get; set;}

// perform an edit and then a split as one operation.
QueuedTask.Run(() =>
{
  var queryFilter = new QueryFilter();
  queryFilter.WhereClause = "OBJECTID = " + oid.ToString();

  // create an edit operation and name.
  var op = new EditOperation();
  op.Name = "modify followed by split";
  // set the ExecuteMOde
  op.ExecuteMode = ExecuteModeType.Sequential;

  using (var rowCursor = fc.Search(queryFilter, false))
  {
    while (rowCursor.MoveNext())
    {
      using (var feature = rowCursor.Current as Feature)
      {
        op.Modify(feature, "NAME", newName);
      }
    }
  }

  op.Split(layer, oid, splitLine);
  if (!op.IsEmpty)
  {
    bool result = op.Execute();
  }
  // else
  //  The operation doesn't make any changes to the database so if executed it will fail
});