There are a number of options here:

• The least acceptable option would be for a nurse who is wearing gloves to gently remove the body of the deceased from the operating table and place on a trolley which can then be removed to a quiet area in the department until those designated by the family to perform Last Offices arrive. However, unless this is witnessed by someone trusted by the family, they may still feel that their cultural needs have not been met as they have no guarantee that their loved one was not desecrated by being touched by unsuitable ungloved hands.
• If there is a spare operating table in the operating theatre department the patient could remain on the table and be removed to a quiet area in the department until those designated by the family to perform Last Offices arrive.
• Whenever possible arrange for the chevra kadisha to attend to prepare the body of the deceased for burial. Ideally this should be done before removing the body from the table, but, if there is no option but to remove the deceased, this can be done following this.

You are correct, if a death is to be referred to the coroner, cannulae, drains etc should be left in place.  If the newly qualified nurse will not listen to what you are telling her you need to explain to her that you are certain what you are saying is correct and suggest that you both consult another member of the healthcare team to check.