Accidental death of both targets, along with the achievement of the Silent Assassin rating (Professional Difficulty). The gunshot while chasing Mark Parchezzi was intentional due to the fact that a gunshot must go off in order to kill Parchezzi (a glitch). If you find it too hard for Parchezzi to shoot you (and stay alive plus pushing him down before the guards come), you can alternatively grab Mark, shoot from your handgun, then push him off to cause the kill.
(4.40)
