Charles Ellicott Commentary 2 Corinthians 2:5

"But if any hath caused sorrow, he hath caused sorrow, not to me, but in part (that I press not too heavily) to you all." — 2 Corinthians 2:5 (ASV)

But if any have caused grief.—The man who had been the chief cause of his sorrow is now prominent in his thoughts. He will not name him. He is, as in 1 Corinthians 5:1–5, and here in 2 Corinthians 2:7, “a man,” “such a one.” The abrupt introduction of the qualifying clause, “but in part,” and the absence of any authoritative punctuation, makes the construction ambiguous.

It admits of three possible explanations:

1. “If any have caused grief, it is not I alone whom he has grieved, but in part, to some extent—not to press the charge against him too heavily—all of you.” They, the members of the Corinthian Church, were really the greatest sufferers from the scandal which brought shame upon it.
2. “If any have caused grief, he hath not grieved me, save in part” (i.e., he is not the only offender), “that I may not press the charge against all of you—so that I may not treat you as if you were all open to the same condemnation, or had all caused the same sorrow.”
3. Combining parts of (1) and (2): “It is not I whom he has grieved, save in part, that I may not lay the blame on all of you.”

Of these, explanation (1) seems the simplest and most natural.

In any case, it is important to remember that the position of the pronoun in the Greek, “me he hath not grieved,” makes it specially emphatic.