(concurring) :
I concur in the result. I rely solely on prosecutorial misconduct with regard to the witness’ claim of privilege rather than on the cumulative-error approach of the District Judge and my colleagues, which I think substitutes federal judges’ notions of fair play in state criminal trials for clear standards of constitutional due process.
Here, I think that the prosecutorial misconduct amounted to an effective denial of the right of confrontation, but only because of the coincidence of the *359following four elements: (1) the prosecution could not reasonably believe that the'witness would not assert his privilege, (2) the prosecution commented, in closing argument, on the witness’ refusal to testify, (3) the inference that the jury was asked to draw supplied an affirmative element of the prosecution’s c.ase, and (4) there was no curative instruction. These elements, I think, distinguish this case from Frazier v. Cupp, 1969, 394 U.S. 731, 733-737, 89 S.Ct. 1420, 22 L.Ed.2d 684.