I wanted to correct one thing that I said. The “law of agency” is usually applied to civil and commercial transactions, but applies to third parties and can be either explicit or implied. It is as though my boss is acting, not me.
On the other hand, attorney/client privililge does extend to translators and non-attorney subordinates in the same vein, unless I was not a subordinate but merely some third-party who heard the confession first. So, a work relationship must exist between me and my employer for his privilege to extend to me.
I would agree that the interpreter or signer for a priest is also their subordinate during a confession and the government cannot compel testimony against the penitent.