Seems like the car was turning relatively slowly away from the ICE officer. At 00:18 in the video when you can hear the gunshots, he's not in the path of the vehicle. Even if he somehow thought the vehicle was heading towards him, it looks like he could have easily stepped back.

If a masked federal law enforcement officer can shoot someone with impunity in a situation that could have easily been avoided, then we are in a very dangerous place.