Why did the Supreme Court recall Pakistan's second Chief Justice during the hearing on Tribunal Rules?

In one of the candid moments during the hearing concerning tribunals before the Supreme Court yesterday, the Bench recalled Pakistan's second Chief Justice..The Bench of Justices L Nageswara Rao, Hemant Gupta and S Ravindra Bhat was discussing whether officers heading tribunals can also be elevated as judges of the High Court, when the second Chief Justice of Pakistan was cited as an example.."[Tribunal members are] Not only elevated as judges of the High Courts, but sometimes they go on to become Chief Justices... like Justice (Muhammad) Munir who went on to become the Chief justice of Pakistan."Justice Ravindra Bhat.The Court was hearing a petition filed by the Madras Bar Association challenging the 2020 Rules on tribunals. Senior Counsel Arvind Datar was addressing the point of exclusion of advocates with long standing from being considered for appointment as judicial members in ten tribunals..Justice Gupta asked Datar as to why was it incorrect or inappropriate to exclude advocates from being considered for the post of judicial members in these specific tribunals..While answering this question, the argument steered in the direction of elevations made to the High Courts from the Bar as well as from the tribunals. Datar said that judicial members of the tribunals are eligible for elevation and there is no rationale for excluding advocates from this opportunity to occupy posts in tribunals..Adding to Datar's point, Justice Rao said that there have been instances where tribunal members were elevated to the High Courts. This is when Justice Bhat and Datar spoke about Pakistan's Justice Munir, who was the first President of the Income Tax Appellate Tribunal back in 1940, in undivided India.."In fact in Pakistan Supreme Court, President of Tax Appellate Tribunal was elevated and later became Chief Justice."Justice Bhat.Justice Munir was elevated to the High Court of Lahore in 1942 and subsequently went on to become the Chief Justice of the Lahore High Court post-Partition. He went on to become the second Chief Justice of Pakistan..Recalling Justice Munir's beginnings at the ITAT, Justice Bhat agreed that elevations to Constitutional Courts can happen from Tribunals..This anecdote purportedly strengthened Datar's argument, who proceeded to argue that if ten tribunals in India under the new 2020 Tribunal Rules do not allow lawyers of long standing to be considered for appointments as judicial members while the other tribunals do, these Rules ought to be struck down as manifestly arbitrary..The challenge against these Rules is also mounted on the grounds of its retrospective application and for being in the teeth of the Supreme Court's judgments delivered on tribunalisation in 2010, 2015, and more recently in the Rojer Mathew case, where the 2017 Rules were struck down by a five-Judge Bench..Against principles of Separation of Powers, Independence of Judiciary: Madras Bar Association moves SC challenging 2020 Tribunal Rules.The problematic aspects of the 2017 Rules appear to be revived in the Rules of 2020, the petition assailing these Rules says. It adds that the Rules are also against the principles of judicial independence and separation of powers.