The rule exists because a decision reached after hearing only one side is not a decision — it is an outcome. Judicial conduct codes prohibit ex parte communication on substantive matters and require prompt notice where a narrow exception applies.
Court staff are not a loophole
Communications routed through a clerk or courtroom representative can carry the same information to the bench. The question is not who typed the message but whether one side had a channel the other did not.
How it is proven
Not by suspicion. By headers. The recipient line of an email, the docket receipt for the same filing, the service notice, and the case-management event history together establish whether a communication duplicated proper service or supplied a separate lane.
The documented example
A Courtroom T-611 representative emailed filed papers to the assigned judge and stated the State would receive them. The pro se filer does not appear on the recipient line. See the routing email.