The artist Si Lewen. One of the Ritchie Boys. Young male European Jews who fled Germany for the United States prior or during WWII, joined the U.S. Army, trained in intelligence work and interrogation, and returned to Germany with the U.S. Army.
Lewen's own website states that he "was among the first soldiers to arrive at Buchenwald concentration camp after its liberation," which you thought would have meant that he knew that there were no gas chambers at Buchenwald. Nevertheless, that didn't stop him from creating a piece of "art" titled "Procession at Buchenwald" which a fawning review in the Herald Statesman said "illustrates the procession of victims into the Buchenwald gas chambers, as well as the march of mankind into a dehumanized future."