I see these verses as totally deferent then you, Br. Clark.
The Law makes (has already made) the judgement and we are to judge the
breaking of the Law, but not the person or the Law.
Matthew 18:15 "If your brother sins against you, go and rebuke him in private. If he listens to you, you have won your brother. 16 But if he won't listen, take one or two more with you, so
that by the testimony of two or three witnesses every fact may be established. 17 If he pays no attention to them, tell the church. But if he doesn't pay attention even to the church, let him be like an unbeliever and a tax collector to you.
I believe James is telling us that by speaking evil of someone we are circumventing the law and making a judgement we are not qualified to make. On the other hand, Christ is telling us not to allow unrepented sin in the Church.