Jacob (James) understood Jewish rhetoric and hyperbole better than most who read the Scriptures today. Anyway, where are all of the other ossuaries claiming to be the “brothers” of Yeshua?
When did the practice of identifying the deceased as Christian begin? At some early point it became standard practice. This ossuary might be an early example of an unusual practice for the time. Jewish ossuary burial was a short lived phenomenon. There really aren’t that many of them.