Can a barrister representing a party have undisclosed social contact with a Judge who has reserved a decision in a proceeding in which the Barrister appeared?
I would hope that most Barristers would have said "No".
The High Court in Charisteas v Charisteas  HCA 29 has emphatically overturned a Full Court of the Family Court decision in which a 2:1 majority held that this conduct gave rise to no appearance of bias.
In a unanimous decision, the HCA held that this conduct was contrary to established principles guiding the inability of judges and counsel who appear before them from having undisclosed social contact. The decision is a delight for its succinct and emphatic disavowal of any such conduct.
Here's the relevant principle guiding such conduct - which all barristers should note:
"13. Ordinary judicial practice, or what might be described in this context as the most basic of judicial practice, was relevantly and clearly stated by Gibbs CJ and Mason J in Re JRL; Ex parte CJL in 1986 by adopting what was said by McInerney J in R v Magistrates' Court at Lilydale; Ex parte Ciccone in 1972:
"The sound instinct of the legal profession – judges and practitioners alike – has always been that, save in the most exceptional cases, there should be no communication or association between the judge and one of the parties (or the legal advisers or witnesses of such a party), otherwise than in the presence of or with the previous knowledge and consent of the other party. Once the case is under way, or about to get under way, the judicial officer keeps aloof from the parties (and from their legal advisers and witnesses) and neither he nor they should so act as to expose the judicial officer to a suspicion of having had communications with one party behind the back of or without the previous knowledge and consent of the other party. For if something is done which affords a reasonable basis for such suspicion, confidence in the impartiality of the judicial officer is undermined."
And here's what the Court said about what had occurred:
14. In this matter, what is said might have led the trial judge to decide the case other than on its legal and factual merits was identified. It comprised the various communications between the trial judge and the wife's barrister "otherwise than in the presence of or with the previous knowledge and consent of" the other parties to the litigation. Indeed, given the timing and frequency of the communications between the trial judge and the wife's barrister, it cannot be imagined that the other parties to the litigation would have given informed consent to the communications even if consent had been sought, and it was not. The communications should not have taken place. There were no exceptional circumstances.
15. A fair‑minded lay observer, understanding that ordinary and most basic of judicial practice, would reasonably apprehend that the trial judge might not bring an impartial mind to the resolution of the questions his Honour was required to decide. The trial judge's impartiality might have been compromised by something said in the course of the communications with the wife's barrister, or by some aspect of the personal relationship exemplified by the communications. Accordingly, there is a logical and direct connection between the communications and the feared departure from the trial judge deciding the case on its merits.