Wow. So they have the struggling man on the ground and two men approach from the left of frame. What’s shown below is not graphic, but it is screenshots from the video.
Edit: Leaving it up, but my initial analysis was incorrect. Pink jacket video is now available. First shooter was different. Man that walks off frame toward camera in this video is the one that recovered the gun. Has it in his hands as he is walking away. Link to new video.
At 17 seconds in, several of the officers have stepped back a bit, one of the late arrivals has turned to leave, and so the guy on the ground no longer has bodies and activity all over him.
The man in the green hood takes a step back, and draws his weapon.
About two seconds later, the man in the green hood takes a firing pose and a shot is heard.
All of the thugs who were attacking the unseen figure step away and reach off their weapons.
A second or two passes. The figure on the ground does not seem to move.
One of the last men to step clear (black beanie) takes several shots
In the video, the two men who arrived late (including the man who opened fire first), are seen leaving the frame quickly.
Without wanting to brew conspiracies, as I know ICE is pretty ragtag. Is that weird? Their cop cosplay outfits don’t quite match the others.

It does seem the gun was not in his possession when he was shot: https://imgur.com/a/ice-taking-victims-holstered-gun-before-shooting-started-NtnH5Hv