Surrendering :thinking
More like he tried keeping his back to the police, so that he could conceal his attemt to unholster his weapon.
I'm looking at the FBI video, not something cobbled together from who knows where. The video you linked to skips several seconds and then focuses on what can definitely be determined to be the kill shot.
If you stop the FBI video at the 9:16 mark and then advance frame by frame you'll see what may well be a different scenario.
9:16 - Finicum hits the snowbank while trying to go around the roadblock. There are at least two FBI guys behind the silver pickup with the headlights on at screen right and what appears to be one more behind the blue pickup at screen left. The latter guy jumps into the path of Finicum's truck.
At that point the camera leaves the scene, refocuses on an approaching chase vehicle and we get back to Finicum at 9:20. Finicum can be seen exiting the truck and the FBI guy in the brown jacket is on the ground directly behind the blue pickip and at the right, rear corner of Finicum's truck. Advancing frame by frame from there we see the shot get a little out of focus but at 9:21 Finicum is definitely out of the truck. His hands go up immediately.
Through 9:25 Finicum's hands are up. The guys that were behind the silver pickup have moved across the road. One is now at the rear passenger side of the blue pickup and the other is in front of the white truck in the middle of the road. The guy in the brown jacket has moved to the rear bumper of the blue pickup. From here I'm going to refer to the guys by position. Position 1 is the guy with the blue jacket at the passenger side rear tire of the blue pickup. Position 2 is the guy in the brown jacket at the bumper behind the blue pickup. Position 3 is the guy in the grey jacket in front of the white truck in the middle of the road and Position 4 isn't in view but he's the guy that comes out of the woods screen left later on.
We are at 9:25. P1 is standing and has his weapon drawn on Finicum (F). P2 is crouched behind the blue truck. P3 is standing at the passenger side front fender of the white truck in the middle of the road. F is standing roughly 6' outside the drivers side door of his truck with his hands up. He is moving parallel to the road and away from his vehicle to the rear of it. You can advance a few frames and not much changes but at 9:26 the focus changes then comes back a second later.
At 9:26 P1 has moved a step farther back toward the front of the blue truck and P2 has stood up. In the next couple of frames P1 begins to move away from the truck and toward F's front. F still has his hands up. At this point F's hands drop but he isn't reaching. P2 has turned and is running back toward the middle of the truck in the middle of the road. P3 has moved to a defensive position behind the cab of the blue truck and may be lined up on F (It's hard to tell because the colors blend together and the focus isn't great).
In the 9:28 segment F appears to be skidding to a stop. His arms are out to each side with forearms turned down. P2 is obviously heading for cover which may be an indication that a shot was fired.
In the next several frames F's right hand comes down to his left side and he appears to double over slightly. F's has turned slightly toward the trucks and P1 has moved into the snow by 10' or so putting him roughly in front of F. This series is indicative of F being shot and reacting to the impact. P2 has a pistol in his right hand and he may well have AD'd striking F.
By 9:30 F has his left arm up and his head turned to his truck. He appears to be yelling at someone in his truck. His right hand is still at his side but he doesn't appear to be going for a weapon.
At 9:31 me makes a move to his waist with both hands and at 9:32 he is definitely going for a gun. P4 has also emerged from the woods more or less behind F. At 9:33 P4 takes the shot that puts F down.
Based on the totality of the events I don't think the FBI acted unlawfully during the takedown but I do believe that they shot first and did so, intentionally or not, while F was "hands free".
-edit-
Almost forgot, here is the video I was citing
