Do you think that God has not? If so, what would make you so sure?
Are you one of Christ's apostles? You had just recently asserted that only those apostles had authority to hear confession (and in other comments you spoke of absolution).
If so...is it you who are "retaining", as "retaining" thus withholding forgiveness for what you apparently consider "a sin"(?).
There are passages of Scripture which indicate that we all must forgive sins; Mark 11:26
Matthew 6:14-15 (NASB)
What now? Label whatever it is the man has done (which you demonstrate that you perhaps think is needing God to "get over it") is not "transgression" per se, but some other type of "sin" -- a differing definition stretched for (possibly even insisted upon) in order to provide needful additional wiggle room for snake-y Catholic theological explanations (and the resulting verdict of damnation pronounced for those in disagreement with the snakes)?
I have found forgiveness of my own sins, far outside the (theologically speaking) narrow confines of Catholicism.
Do you have a problem with that, beyond possibly mere jealousy, that is?
I am not alone in this. You've already been told how it can be known that one is forgiven, of God (without a so-called priest saying the words).
Perhaps...you may be underestimating the Holy Spirit?
As some [Greek] Orthodox might put it (and have, upon occasion) for this exact kind of context;
But;
we cannot say where the spirit of the Lord is not.
How do you know those sins were forgiven? Did you get a receipt?