‘But if any has caused sorrow, he has caused sorrow, not to me, but in some measure (so that I do not press the case too heavily) to you all.'
Indeed the reason that he dealt with the offender so strongly in his letter is not because of the sorrow the man has caused him, he does not think of that, but the sorrow he has caused, (up to a certain point, for he does not want to overexaggerate), to the whole Corinthian church. However he stresses that he does not want to overstate the case. The sorrow that they have experienced is probably not equal to his own. (This very concern not to overstate the case stresses that when he speaks of the depths of his own sorrow he means every word of it).
‘But in some measure (in part).' To a certain measure, to a certain level.