The official headnote to Durueke (PTA: AZ applied, proper approach)  UKUT 197 (IAC), which reads more like a memo to self or some sort of passive-aggressive intra-judge fisticuffs:
(i) In reaching a decision whether to grant permission to appeal to the Upper Tribunal on a point that has not been raised by the parties but which a judge considering such an application for permission considers is arguably a Robinson obvious point or other point falling within para 3 of the head-note in AZ (error of law: jurisdiction; PTA practice) Iran  UKUT 245 (IAC), the evidence necessary to establish the point in question must be apparent from the grounds of appeal to the Upper Tribunal (whether or not the appellant is represented at the time) and/or the decision of the judge who decided the appeal and/or the documents on file. The permission judge should not make any assumptions that such evidence was before the judge who decided the appeal. Furthermore, if permission is granted on a ground that has not been raised by the parties, it is good practice and a useful aid in the exercise of self-restraint for the permission judge to indicate which aspect of head-note 3 of AZ applies.
(ii) Permission should only be granted on the basis that the judge who decided the appeal gave insufficient weight to a particular aspect of the case if it can properly be said that as a consequence the judge who decided the appeal has arguably made an irrational decision. As the Court of Appeal said at para 18 of Herrera v SSHD  EWCA Civ 412, it is necessary to guard against the temptation to characterise as errors of law what are in truth no more than disagreements about the weight to be given to different factors, particularly if the judge who decided the appeal had the advantage of hearing oral evidence.
(iii) Particular care should be taken before granting permission on the ground that the judge who decided the appeal did not “sufficiently consider” or “sufficiently analyse” certain evidence or certain aspects of a case. Such complaints often turn out to be mere disagreements with the reasoning of the judge who decided the appeal because the implication is that the evidence or point in question was considered by the judge who decided the appeal but not to the extent desired by the author of the grounds or the judge considering the application for permission. Permission should usually only be granted on such grounds if it is possible to state precisely how the assessment of the judge who decided the appeal is arguably lacking and why this is arguably material.Durueke (PTA: AZ applied, proper approach)  UKUT 197 (IAC)
I confess I could barely reach the end of the headnote on this one. Why this couldn’t have just been said in some internal training session or failing that a note left on the staff room fridge I’m not sure. If anyone reads the actual determination and spots anything interesting, let me know.