While I have an ethical duty not to permit the use of racist terms in the courtroom, I wouldn't go so far as to say that "Oriental" is one of them. Am I wrong?

That depends on the nationality of the defense attorney.

Since the defense attorney was Korean, his reaction could have been genuine.

If the defense attorney had not been Asian, you would have been correct in dismissing his objection summarily as patently contrived.

Only an Oriental could be offended by the use of the word "Oriental" to describe an Oriental since the the word is purely descriptive, and not disrespectful, within the vocabulary of a non-Oriental who has no reason to be be knowledgeable about subtle differences, physical or otherwise, between Orientals from different countries within the Orient.

An Oriental might perceive an insult where none exists only because he believes that everyone should be able to distinguish between Orientals from different countries just as he does. However, this is an unrealistic expectation.

A person who does not live in the tropics can be forgiven for describing all tropical plants as "tropical" because he or she doesn't know the specific name of the plant in question. This is not an insult to the plant or to those who know the individual names of all tropical plants.