His shirt movement is difficult to explain with a rifle shot from any angle.
The necklace movement indicates the epicenter, not only from the area where it snaps but from its trajectory up and around his right shoulder around his back where it rest on the back of his left shoulder.
The shirt deformation on the back of his collar indicates a extremely quick gas expansion which is followed by the shrapnel lifting the front of his left collar up around his face. Combine this with the necklace movement and you get the epicenter of the energetic event.
Watch the cavitation of his chest and stomach traveling away from the epicenter. It’s the opposite direction of the cavitation of his neck and face, another sign of the epicenter.
Look at his knees… they quickly close and almost cross as he lifts his body from the chair. His elbows turn as his hands clasp, crossing his knuckles and flexing his wrist. His left leg even extends as he falls out of the chair.
American Buddhist Net 