2 Cor. 2:5-11
(If you've already mentioned this, sorry for the redundancy - haven't quite caught up to this point!

)
I thought it interesting that the forgiveness came after the punishment was sufficient.
Sufficient for what?
The offender was sorrowful which could be an indication of repentence.
In 1 Cor. 5:1-5 - the following punishment is inflicted, "hand this man over to Satan for the destruction of the flesh, so that his spirit may be saved on the day of the Lord."
This may not be the same person, but the progression is clear - consequences are inflicted on the offender in hopes that the offender will be saved; sufficient consequences result in sorrow which brings forgiveness. Implied, I think, in IICor.2 is that a godly sorrow that has led to repentence. (II Cor. 7:10) The church is then free to forgive, comfort and restore fellowship.
So, godly sorrow => repentence <= forgiveness
I don't think we are helping an offender by making it easy for them to continue living a lie or living in their sin. But we call it "forgiveness"...often enough.
The more I think about - and thanks to seeds planted by Gene in this thread - the more I am understanding forgiveness as a transaction. There is a kind of exchange involved. Maybe, the offended "forbear" (vs. forgive) when the offender refuses to acknowledge the offense.