I assume that the pilot had reasonable concern that if Jafari had managed to open his door, he could have yanked the cyclic and possibly rolled the helicopter over with catastrophic consequences.
However, why was it necessary for a private pilot to do a rotors running pick up in the first place. Why not arrive & shut down - then any disagreement could have been handled on the ground. The pilot could have loaded and briefed his passengers fully - as he is required to do by law - before firing up and lifting. Just a thought!