I can make a couple general points due to my municipal/county policing experience and that's the average federal police officer or agent receives on average far less training than the average city cop or sheriff deputy. For example in my state POST requires a minimum of 664 hours of training and my department forced us to do nearly 8 months worth plus an additional four months of on the street training.
Federal training is 12-20 weeks depending on the specific agency(e.g. FBI, US Marshalls, Ice, etc). I quickly looked up training for ICE and it's 13 weeks. They do 12 weeks of standard FLETC training and an extra week of whatever else. To put this in perspective this is nearly 1/3 of the training I had to do a couple decades ago. If I heard correctly my old department tacked on a couple additional weeks on top of that.
Many municipal departments, including the one I worked in had it explicitly stated in the general orders that officers were not to place themselves in the way of fleeing vehicles as a pretext for self defense to use lethal force. Federal agents likely have much looser standards and only have to abide by the case law like Graham v Connor and Tennessee v Garner. I believe there are a couple newer cases (Barnes v Felix) that just recently came through. Here the SCOTUS found even the officer jumping in front of the car to prevent it from escaping, ie intentionally placing himself in harm's way, was still justified use of lethal force.
Yesterday, the Supreme Court decided Barnes v. Felix, an important Fourth Amendment case for law enforcement involving the Fifth Circuit’s “moment of threat” doctrine, which only analyzes the reasonableness of the use of force at the moment the officer deploys deadly force.
imla.org
I personally disagree with such an approach but if we're talking about pure legality chances are the ICE agent was fully protected in his use of force.
