Yes. I went to law school almost 30 years ago, and there was certainly precedent for such decision even back then. Again, see the LoRacca cases from New York during the mid-70s. LaRacca (sp?) was a priest who was a practicing defense attorney who filed a number of civil suits and appeals because the trial judge forced him to remove his Roman Collar. None of those appeals prevailed.
I know there is a dress code for attorneys in the courtroom,
but maybe the judge in this case thought the ashes made the attorney look unkempt.