Yes. I'm not sure if I'm understanding your question properly though. For instance, I came across a case the other day where a self-represented litigant made unsworn representations of fact from the bar table, which were not admissible, but evidence and submissions were being confounded.

Is there something more specific you're referring to? Are you looking for witnesses who refuse to take an oath or affirmation? Or those for whom the oath is inadvertently not administered? Or deliberately omitted by the Court?

Sorry, we don't allow throughout history questions. These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to re-compose your question and submit it again. Alternatively, questions of this type can be directed to more appropriate subreddits, such as /r/history or /r/askhistory.