The video shot by the agent in question is the most indicative of the car hitting the agent, as CBS found:
https://www.cbsnews.com/minnesota/news/experts-analyze-new-v...
>Johnson said his biggest takeaway from the video was a crunching sound he heard immediately before the gunshots, which he believes is the sound of the SUV hitting the ICE agent.
>"That data point for me shows that there was contact made with the agent, who is now in reasonable fear, who could clearly articulate being hit with an SUV as reasonable fear of great bodily harm or death. And then the shots were fired," said Johnson.
If a car is driving toward me (essentially the only way it could cause me harm) and I shoot the driver in the head, then the car keeps driving toward me and, lacking a driver, threatens not only me but also others in the immediate vicinity because it will keep moving. (Witness how the car in this instance keeps going and crashes.)
Another scenario. It's illegal (at least in Florida) to make a left or right turn while pedestrians are in any part of the crosswalk. Suppose I'm crossing the road, duly within the crosswalk and with a valid "walk" signal, and someone makes a turn while I'm in the crosswalk and is headed right toward me. The car being a lethal weapon, am I justified in drawing my firearm and shooting the driver in the head in self defense?
Not in Minneapolis because it is a duty to retreat state for regular citizens. Therefore your scenario really creates a false equivalence because the cops have special privileges to kill people in the case they use a 'deadly weapon' due to the 'fleeing violent felon' exceptions for cops that allows them to be a summary executioner in cases of clear flight.
Still, whether this (or any) federal officer violates a person's Fourth Amendment rights (by way of exercising excessive force) is subject to a standard of objective reasonableness under the circumstances. E.g., Graham v. Connor, 490 U.S. 386 (1989). That applies regardless of state law (on account of the Supremacy Clause).
Given ICE's very narrow jurisdiction (despite their current aggressive actions and the clear approval of their federal executive superiors for that aggression) this is a real concern about their content even before the shooting.