The Ethos article is about the criminal case. The case involved the Student Code of Conduct is a totally different matter. There is a very long list of violations and a much lower threshold of evidence for guilt than in a criminal case. At this point, we don't even know what violations Leath found him guilty of. Maybe Leath threw him under the bus, but I doubt it. It is possible that Leath looked carefully at the evidence and thought that Bubu was indeed guilty. If so, then it would be unethical for him to have done anything else. I recognize this is speculation, but I think we at least owe Leath some benefit of the doubt until we know more facts.
the burden for student misconduct is preponderance of evidence, the same standard applied by the ALJ who found the evidence did not meet even this low standard. Also, the ALJ actually heard 10 hours of testimony. Leath didn't.