5. Mark was charged with Rape as a principal by direct participation while his employer, Ado, was charged as a principal by inducement for forcing Mark to commit rape by holding him at gunpoint. Mark was acquitted by the trial court for having acted under the compulsion of an irresistible force. Meanwhile, Ado was convicted of Rape. Ado appealed on the ground that he cannot be held liable because there can be no crime if there is no principal by direct participation. Is the argument of Ado tenable? Explain.