A disciplinary hearing last week for Donald Trump‘s ex-Department of Justice official Jeffrey Clark showcased the high bar prosecutors must reach in their effort to prove alleged crimes the former president and others are accused of committing in the buildup to the Jan. 6 Capitol riot.

Clark, 56, is fighting to avoid disbarment in Washington, D.C., as he faces Board on Professional Responsibility proceedings over allegations of dishonest conduct in the aftermath of the 2020 presidential election. The disbarment trial continued for a third day on Thursday with a witness called by Clark’s defense, Donald Elliot, a Yale legal expert who said punishing the former DOJ official would set a dangerous and “chilling” precedent.