Anons, in the sequence is a photo that's not being circulated in the social media circles. After the physical confrontation the shooter appears to be lifting his shirt in an effort to draw his weapon as the patriot is stepping back (look at his foot placement in relation to the fence). It appears that the spray may have been in response to the gun being drawn, and the gun in response to the slap in the face.

Also, could the reflection in his glasses actually be showing the time of impact instead as the round is penetrating the glasses?

Pictures sauce:

https://www.denverpost.com/2020/10/10/dueling-denver-rallies-fatal-shooting-photos/