“ As we pointed out in Barber v. Page, one of the important objects of the right of confrontation was to guarantee that the fact finder had an adequate opportunity to assess the credibility of witnesses. ”

“ Page should be given retroactive application. We think that it should.
Clearly, petitioner's inability to cross-examine Dunston at trial may have had a significant effect on the 'integrity of the fact-finding process.' Linkletter v. ”