[barker]

When the camera shows the crowd just after Trump is taken off stage most people are going towards the action. There is one man wearing a brown shirt and Trump hat moving fairly fast away from it. He came from the direction Trump had just been looking. Maybe there was more than one.

[Syncro]

Good observation

[TigersEye]

I saw the same thing. Here are separate two videos of the incident that show him.

The Donald is rushed off the stage by Secret Service while speaking during Reno rally after a 'Republicans against Trump' protester causes chaos in the crowd over fears he had a gun

In the video on that page at 0:22 seconds you can see a guy in a flannel shirt or jacket running away from the commotion, a smile on his face, and after that you can see several people looking in his direction and they look upset and/or concerned.

Secret Service Swarms in to Protect Donald Trump After Scare in Reno 11/5/16 (Youtube 4:45)

Here is a longer video from a different camera of the same incident. At about 0:44 seconds into the video you can see the same guy, wearing a black cap with white print on it, running away. At about the 1:00 minute mark you can see several people's heads snap around looking back in the direction he went.