As the Masters of the Senior Court Costs Office “respectfully disagree” over the new test of proportionality, and its application to additional liabilities (after the event insurance in particular) seasoned practitioners might wryly observe that this confusion dates back to the fateful decision of Lord Woolf in Lownds v The Home Office. Having attended hundreds of detailed assessment hearings since 1999, I would suggest that the concept and application of the proportionality test is as mystifying to the Costs Bench as it is to mere mortal practitioners. That is far from a criticism of Costs Judges. It is an observation that the concept of proportionality and how it should be applied within the Rules is highly subjective. Add to that the factual matrix of any particular case and litigants need not only a Costs Lawyer, but a Costs Lawyer with a Crystal Ball. For what my own respectful view is worth however, the BNM “standing back and looking again at the assessed figure” decision of the Senior Costs Judge cannot stand for three fundamental reasons: firstly, it imputes double jeopardy; secondly it is contrary to normal remedial principles of tort / contract law; and thirdly it is arbitrary and unjust.