Is a criminal defendant's Sixth Amendment right to Compulsory Process or Fourteenth Amendment right to due process violated when access to impeaching and exculpatory evidence in third-party confidential medical records about a government witness is denied?

Is a criminal defendant's Sixth Amendment right to Compulsory Process or Fourteenth Amendment right to due process, right to present a defense, and a right to a fair trial violated when what can be loosely defined as a criminal defendant's "constitutionally guaranteed access" to impeaching and exculpatory evidence contained in third party, confidential medical and mental health records about a sole government witness with severe indicia of dysfunction (that implicates the witness's competency), is denied while access to the same records if held bv a government entity is granted ? 1 STATEMENT OF