http://decisions.fca-caf.gc.ca/fca-caf/decisions/en/item/72231/index.do 
Canada v. ExxonMobil Canada Hibernia Company Ltd. (June 25, 2014 – 2014 FCA 168) was an appeal from an unreported decision of the Tax Court ordering CRA to answer four disputed discovery questions. The Federal Court of Appeal held that the Tax Court had acted within its discretion in making the order:
[3] The Crown submits, as it did before the Tax Court, that the discovery questions relate to an issue the Crown is conceding and, if necessary, it would amend its pleadings to reflect the concession. This, it says, would render the questions irrelevant. In its memorandum, the taxpayer submits, as it did before the Tax Court, that even if the Crown were allowed to amend its pleadings, the issue would still be in play and be the proper subject of discovery questions. The taxpayer invokes the Court’s discretion in the interests of justice to hear a moot issue, its obligation to determine tax disputes based on the actual facts and the law, and its power to address an abuse of process.
[4] The Tax Court declined to rule definitively upon these submissions. In its view, as the Crown had not moved to amend its pleadings, the matter was premature. The Court could have dealt with those submissions to take a potential issue off the table but declined to do so. Both of these options were discretionary and were open to the Tax Court in these circumstances.
The decision is difficult to contextualize since there is no information about the disputed questions or why they might have continued to be in play even if the Crown conceded the issue to which they were addressed. It would be helpful if the Tax Court published the reasons for the original order.