Since I haven't seen anyone make a post on this, I'll take a crack at it. Among other thoughts I have, the defenses of the shooting I have seen all seem either blatantly nonfactual or intentionally vague to avoid having to discuss the facts in the first place. What seems to be agreed on is that Alex Pretti was unarmed at the time of the shooting, never attacked the ICE agents who shot him, and had effectively surrendered at the time he was shot. I haven't seen serious disagreement about that, or any other consistent narrative of events.
What I have seen is intentionally vague accusations leveled at Alex Pretti. For example, “He was a domestic terrorist.” How was he a domestic terrorist? Or “he was impeding law enforcement.” How was he impeding them? Or, “he provoked agents.” How was he provoking them? And if “provoking” just means bringing a gun to a protest, I don't think there's anything illegal or immoral about provoking. The other class of accusations seem to be things that wouldn't justify deadly force on their own but are aimed at implying Pretti did something more that did justify deadly force. For example, “he approached the agents with a weapon,” implying that he threatened them with the weapon even though he did not.
I remember the discourse around Kyle Rittenhouse being similar, with equally vague criticisms like “he was provoking people.” (Again, if provoking just means carrying a firearm, then I don't think there's anything illegal or immoral about provoking.) Or “he shouldn't have been there,” which could be said ex-post facto about any assault victim, and they would probably agree that they'd rather not have been there in hindsight, but does not explain what was unjustified about being there in the first place. Or “he crossed state lines,” which I just find confusing as a criticism because it's not like he'd be safer if he'd gone to an equally dangerous place closer to where he lived. Or “he was a vigilante,” when I don't think being a vigilante is automatically bad and it's not illegal. (If you shoot a mass shooter who is killing people, you are a vigilante. Similarly, carrying a gun around to deter crime might be vigilantism, but I'm not sure what's immoral about it.)
Rittenhouse seems to have avoided taking a hard stance on the Pretti shooting, but it just seems weird to me that the people defending Rittenhouse as obvious self-defense haven't recognized that Pretti was also obviously behaving within the bounds of the law. We're seeing all the same media manipulation with Pretti with people just coming out and just saying untrue things about what occurred, and it seems weird to me that anybody is falling for that again. But I guess if you accuse someone of “looking for trouble” and are vague about what that means, then some people will believe that person is a criminal.