Watching some legal movies it struck me as odd where judges are portrayed talking to one of the parties in the absence of the other (ex-parte communication). Say in New Zealand, this amounts to judicial misconduct (Guidelines for Judicial Conduct at [30]):
Communication between the judge and any party in the absence of the other party to the case is not permissible, except in proceedings properly heard ex parte.
Some examples:
In A Time to Kill, the judge is once shown walking down the street friendly talking to the state attorney/prosecutor (Jake and Oliver see them while sitting in a cafe just before Ellen Roark arrives). In another scene, the judge invites Jake to his house to tell him that his application for change of venue is denied.
in Jagged Edge, Teddy just knocks on the Judge Carrigan's door and, although he says that he can't talk to her, she begs him and he lets her in. Funnily enough, they both pretend to be talking about a hypothetical case.
In The Untouchables, Ness talks to the judge in his chambers, shows him a piece of paper where the jurors (as well as the judge himself) are listed to be on Capone's payroll, and persuades him to switch the jury.
Was/is it permissible for judges in the US to talk ex-parte like that? If yes, how come? If no, do the above scenes in the movies essentially portray judicial misconduct?
Related: Ex-parte communication between a Judge and Prosecutor - ethical breach or canon violation?