Some jurisdictions, New Jersey being one example, include provisions of the affidavit of merit statute which addresses situations where a defendant fails to produce a medical record, despite a legitimate request which has been made by certified mail. Under certain circumstances, the statue will allow an affidavit to be presented to the court indicating that despite an appropriate and timely presented request for records with a HIPPA-complaint authorization, such records were never presented and otherwise would have been necessary to have the matter evaluated by an expert.
You can read more practice tips in my chapter Screening the Nursing Malpractice Case, in a text edited by Patricia Iyer, RN MSN LNCC. More information about Nursing Malpractice, Third Edition, 2007 may be found at here.