This episode's headline: False Witness?; SMU Penalty; High Scoring Coaches; Grace Under Pressure. The guests include In Washington: RAYMOND RANDOLPH, Defense Attorney; In New York: ELIZABETH HOLTZMAN, District Attorney, Brooklyn; PAUL SIMON, Musician; In Dallas: WILLIAM STALLCUP, Acting President, SMU; REPORTS FROM NEWSHOUR CORRESPONDENTS: ELIZABETH BRACKETT, in Chicago; KWAME HOLMAN, in Dallas; TOM BEARDEN, in North Carolina. Byline: In New York: CHARLAYNE HUNTER-GAULT, Correspondent; In Washington: JIM LEHRER, Associate Editor