I found a report on the accusations against Pastor Brian Carpenter (link to report).
There are a lot of accusations mixed together there, but the only seemingly concrete, particular, specific accusation was that Mr. Carpenter had stated:
“He [referring to Pastor Moon] also affirmed that he believes that no reprobate person ever gets justification, and that he believes that the baptized reprobate do get forgiveness of sin in some real sense.”
The accusation alleges that "Mr. Carpenter’s statement [is] false and misleading."
The accusation explains that "To state the matter as Mr. Carpenter has is to imply that the sort of forgiveness of sins only known and enjoyed by the elect (WCF 11.1) can be known in some real sense by the reprobate. Dr. Moon has never said this and holds no such view."
But Moon is reported (see this link for the source for the following quotations) as having said: "Again, the complaint alleges TE Lawrence outside the Reformed system when attributing forgiveness of sins and union with Christ to all baptized infants. But the complaint can be raised as well against the author of the Helvetic Confessions. ... What has TE Lawrence said that is more than that? Union with Christ, partakers of his righteousness, sins covered: that is our Reformed tradition."
And again: "TE Lawrence is said to attribute to the reprobate what only belongs to the elect – namely, union with Christ, adoption, forgiveness of sins, and new life. Attributing any of those to the reprobate is, you are being told, contrary to the Standards. But not only is that untrue to the Reformed tradition, it also flies directly in the face of the plain language used in Scripture."
And yet again: "We are told by the complainants that you cannot attribute forgiveness of sins to the potential reprobate. But that is clearly wrong. The unmerciful servant, Jesus says, was “forgiven his debt.” He moved from a state of condemnation to true and real forgiveness. This was no pretended forgiveness. Yet the servant was finally apostate. He failed to live up to the grace shown to him, and so the privilege of that forgiveness was revoked. And that, Jesus says, is how my father will treat each of you if you do not forgive your brother from your heart. This, remember, is addressed to Peter and Christ’s own disciples. It is a parable about forgiveness and apostasy, and gives the complainants no ground at all for their complaint."
And still further: "In attributing to all the baptized some form of union, adoption, new life, and forgiveness, TE Lawrence is speaking the language of our tradition and of our Scriptures. By refusing to attribute absolute and final union, adoption, new life, and forgiveness, TE Lawrence is directly in line with our Standards."
I fail to see how Pastor Carpenter's statement: “He [referring to Pastor Moon] ... believes that the baptized reprobate do get forgiveness of sin in some real sense,” is either false or misleading. Could someone from among Pastor Carpenter's accusers enlighten me? If there is any concern that posting answers to this question publicly would prejudice any case pending in any PCA court, I'm open to receiving answers by email (my email address is available via my blogger profile).