Hoist with his own petard
"Hoist with his own petard" is a saying from a speech in William Shakespeare's play Hamlet that has become proverbial. The phrase's meaning is that a bomb-maker is blown up ("hoist", the past tense of "hoise") off the ground by his own bomb ("petard"), and indicates an ironic reversal or poetic justice. The saying means that a person has been messed up by their own actions.