This episode's headline: Persona Non Grata; Exploring or Exploiting; Lawrence Walsh; MDNMIn New York; ROBERT MacNEIL; Executive Editor. The guests include In Washington: KLAUS EMMERICH Austrian Television: DONALD HODEL, Secretary of the Interior; LAWRENCE WALSH, Iran-contra Independent Counsel; In Boston: ALLEN RYAN, Former Justice Dept. Official; In San Francisco : MICHAEL FISCHER, Sierra Club; REPORTS FROM NEWSHOUR CORRESPONDENTS: JULIAN O'HALLORAN, BBC; STEVE TALBOT, KQED, San Francisco. Byline: In Washington: JIM LEHRER, Associate Editor