‘to confirm or cancel the penalty, or substitute for HMRC’s decision another decision, but only one that HMRC had the power to make. The Tribunal can only rely upon the “special circumstances” provision in paragraph 9 to a different extent than that applied by HMRC if it thinks that HMRC’s decision in that respect was flawed. Applying judicial review principles, the Tribunal must consider whether HMRC acted in a way that no reasonable body of commissioners could have acted, or whether they took into account some irrelevant matter or disregarded something to which they should have given weight. The Tribunal should also consider whether HMRC have erred on a point of law.’