Please reread the OP. The OP is asking about a criminal case. The question is, in fact, one of admissibility in a court of law.
Also, and again, reread the OP, the OP is assuming that a clergyman can repeat stuff said to him in his official capacity as a clergyman, because the seal of confession did not* technically *apply, as though the canon law on specifically the seal was the only moral principle. This violation of privacy would be immoral for reasons both related to, and totally unrelated to, canon law (which by the way is changeable) or civil law.
The Church’s canon law on the matter was instituted because of the immorality of violating someones moral right to privacy here, not the other way around.