I would point to the recognition in Procedure and Practice—where there's a discussion about the role of public servants and their particular function—that indeed they are not the ones making the policy decisions. That is being done by the ministry and by the minister.
There is a discussion there about the types of questions and the questions and topics that are appropriate—or not—for public servants, and that generally committees will accept reasons given by public servants if there are areas where it's beyond the public servant's authority or knowledge. That's where you've seen these types of concerns very much in terms of topics that would be appropriate for public servants, given their very different role in terms of decision-making and also in terms of accountability.