These kind of statistics feel similar to how the National Football League has about 70% of its player population being black while the QB position, the most important position in the sport, is dominated by white guys. On the surface it looks like the problem lies with black people, but in reality this is probably merely the result of how the whole sport is set up, beginning at the childhood stage. The system favors white people, so white boys are more likely to be QBs and more likely to get fostered at an early stage, consequently resulting in an off-balance at the adult level.
It may also be worth doing the maths on the first quoted line in the OP: 24 of 457 whites shot and killed were unarmed, that's a bit above 5%. 18 of 243 blacks were unarmed, that's a bit above 7%. That's such an obvious thing to miss that one has to be suspicious of the author's intentions. Could be an oversight, could be cherry-picked statistical data to support a desired conclusion.
For which reason did Zac Kriegman lose his gig?
I do not know about football, but I think I get the analogy: you are talking about a system that favours white people. Especially in light of my op (which is just one guys analysis), I would really appreciate if you could find something that would support this view. The thread could only benefit from it.
To your calculations:
24 of 457 whites killed were unarmed - 5 %. 18 of 243 blacks killed were unarmed - 7 %. That is a 2 % difference. I would like to mention three things about this.
1) The implicit assumption here is that the amount of unarmed people killed will directly correlate with the total amount of people killed. But it could very well be the case, that when the number of blacks killed would reach the highs of whites killed, it would still stay at 18 unarmed blacks killed. We just do not know that. What we do know is that more whites are getting killed than blacks. And more unarmed whites are getting killed than unarmed blacks. Even though the amount of violent crime between the groups is similar (albeit a bit higher among blacks). For that reason it could just as easily be argued that the total amount of blacks killed is unexpectedly low. If it was as high as whites killed (457), the 18 now unarmed black people killed would be just shy of 4 %. But again, we just do not know if that number of unarmed black people killed would go up or not. Even though I can see how it is more likely to go up than to stay flat or go down, when the total amount of balcks killed would rise the highs of whites killed.
2) A 2 % difference does not strike me as all that significant and as a weird take-away in the face of much more striking information and much more startling differences and numbers: whites killed (457 - 65%) and blacks killed (243 - 35%) make 700 people (100%) killed by the police annually. But blacks commit 53 % of homocides and 60 % of robberies. There is a 25 % difference in number of people getting killed by the police between blacks and whites, even though blacks account for slightly more violent crime.
3) Every single person killed by the police (especially unarmed, but also otherwise) is a tragedy. But this is about perspecitve. The additional 2.500 (but perhaps even 10.000) people killed (mostly blacks) due to de-policing directly linked to BLM are also tragic. But the 2 % difference you pointed out is about 5 people (243*5,25 % (-percentage of unarmed whites killed) = 12,75 = 13 unarmed black people that could be killed without showing anti black bias. 13, but the number is actually 18 - so 5 people that "unjustly" got killed when compared to white unarmed people killed by the police. (Perhaps 6 if you round it down.) So, even though I do not agree with your method (point 1) let's say 5 unarmed black people killed annually is actually the anti-black-bias of the police and could not otherwise be explained. Should we really be "suspicious of the author's intentions" because of that? In the face of at least 2.500 additional homocides due to BLM?
It is worth mentioning that Roland Fryer (black by the way), on whose numbers part of Kriegmans analysis is based, was very diligent: Roland Fryer (Harvard) was so shocked by his own findings that he fired pretty much his whole team, hired a new one and redid everything. Same results. This really goes a long way to make things more believable for me.
For which reason did Zac Kriegman lose his gig? - That is explained in the very first paragraph of the analysis:
"This is the post that I made to Thomson Reuters’ internal social media site, called the Hub, that precipitated a barrage of hateful and racially charged attacks from BLM supporters within the company. When I brought those attacks to the attention of Thomson Reuters’ Human Resources department, my post was censored, and I was told I was not allowed to use any company communications channels (email, teams, the Hub, etc.) to discuss the attacks I had experienced. Receiving no support from HR, I raised the issue with my colleagues and senior leadership over email, for which I was fired. Below is the Hub post that precipitated this chain of events, in full."