There are 2 properties in the Content WIndow that can be set to hide/show the Detail and/or Audit tab from the Content WIndow Preview Pane.  By Default, the boolean flags are set to true (Show).  You can easily set them to false (Hide) in the am_SetParentProperties method in your Content Window code behind.

protected override void am_SetParentProperties()
{
    RG_SetParentProperties();

    ap_CreateDetailPreviewTab = false;
    ap_CreateAuditPreviewTab = false;
}