Have you ever read the gospel of St. John?
Of course I have and also investigated the meaning of the Greek words used. Those sins were forgiven by God and only proclaimed forgiven by the knowledge that God forgives the sins of those who confess and repent. Scripture is clear that only God can forgive sins. We can proclaim that forgiveness through the understanding of scripture.
1 John 1:9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
The arrogance of the RCC in claiming to have that ability is heresy.