"Shocks the conscience" is a generic legal phrase describing any circumstance(s) deemed outrageously wrong or unfair when measured by specific criteria.
In criminal and civil cases where something shocks the court's conscience, the judge is allowed to take matters into their own hands in order to address it.
Depending on the circumstances, a presiding judge has several options when something happens at trial that shocks the conscience of the court.
For example, if the judge determines that the financial compensation awarded in a civil suit fails to meet objective criteria for "fairness and decency," they can invalidate it. In a trial involving a contract dispute, the presiding judge can void the agreement, and in a criminal case, they can overturn the verdict.