My understanding of the witnesses' testimony is that they indeed wanted to circumscribe the exercise of discretion used by the judge. The fear, if I understood the testimony correctly, was that the judge might have recourse to circumstances unrelated to the right of the accused in making this determination.
So I sense that the thrust of the amendment is to direct the judge to those types of considerations in making his order. But again, from my perspective, “may” or “if the circumstances warrant” are pretty much to the same effect, taken in the context of the interpretation of the provision as drafted in the whole.