“The guy in the white suit” apparently saw Ruby coming and saw the gun, that is why he appears to be surprised. The others had not yet had time to react to the sound of the shot.
Yeah but if you look at the photo, the shot has been made, the bullet enters Oswald, he grimaces in pain. Plenty of time for the sound of the shot to reach their ears yet none react to it. I looked this stuff up:
Speed of sound - 343.2 m/s (meters per second)
Speed of .38 caliber bullet from Colt Cobra revolver - 237 m/s
So basically the sound of the shot would have reached their ears pretty much the same time Oswald felt the bullet. Even though the bullet is slower than sound, at 343/237 m/s at those speeds it’s pretty instantaneous. So why would Oswald react but not them? If you watch the video of him being shot, he had absolutely no idea, never saw Ruby coming, so he is reacting to the pain. And in that video the crowd reacts as if it was expecting it just like the photo. No running, or panic, nothing.