There are some problems with this photo being a bullet.
1/ The timing of Trumps position is wrong, he is like this after the first shot and before the 2nd shot.
2/ The length of the bullet. As a rough estimate, call it 1 foot, might be a few inches out. The shutter speed is 1/8000th of a second. This means this bullet is traveling 8000 feet per second. A rough number for a .223 is 3000 feet per second. Despite the error in this calculation, things are still way off here.
What this photo could actually be is the splatter of Trumps ear as it gets pulled into the vacuum trail left by the bullet. This splatter trail does not travel as fast as the bullet, stretches out and disperses over time.
This also helps explain how the photographer could of made such a lucky shot to catch a bullet. Has a bit more time and chance to catch the vapor trail that the bullet leaves in its wake.