On the Redeemer of the Blood

In reading the first verses of the parsha, there is a sense of discomfort on their part regarding the privilege given to the blood savior to kill.
So much so that some believe that his permission is only granted after his sentence is pronounced in court.
However, the HaKetzat reports that Rashi and Rambam believe that it is permissible to kill a person who has been redeemed in the form of a camel.
And how? After all, it is forbidden to murder? Even an alleged murderer.
I thought about why it is said that it is indeed forbidden to kill a redeemer, but that a redeemer is a sinner. This is the one who “warms his heart.” In the sense that he does not control himself and therefore is a sinner.
It is appropriate to discuss whether it is permissible or forbidden to do something in the context of a deliberate situation, which refers to a person making a decision and thus commanding him.
One can ask for forgiveness after the fact, but to order or discuss his prohibition of committing a transgression – this is outside his world of concepts. What good would it do to order someone not to do something that he does unintentionally?!
And assuming that a person who kills is in a psychological situation where he is considered to be in error, who does not control or choose his actions because he feels like it, the discussion of whether he is permitted to kill or not is irrelevant. (Perhaps after the fact he will be obligated to atone)
(Recalls the law’s reference to cold-blooded murder as other, more lenient degrees)
The Torah describes a situation, it’s a given! He’s going to kill! And from there the Torah builds a defensive system of a city of refuge, etc.
What does the Rabbi think about this matter?