Talmudic study

The words of Tana Debi Hezekiah about those who are guilty of death are a worthy subject and I have wondered about it more than once. The definition is that if it is an offense for which there is a severe punishment, even if he does not actually receive it, this exempts him from the light punishment. In other words, it is a law in the offense itself (the punishment is only a sign and not a reason), and not in the punishment. That is as far as the definition is concerned. Now for the explanation.
To understand this, we must also ask in a normal case why one is exempted from punishment under the law of the Kalbdarm? Ostensibly, he is liable to both punishments and must accept both. And will someone who ate garlic and its smell waft back and eat garlic? It seems that the exemption from the light punishment came so that the severity of the serious offense would not be lightened. They want to sharpen its severity and not let anything else overshadow it. For example, if you murdered a person and in the process tore his clothes, we will not kill you and we will also charge you a penny, because that makes a mockery of the crime of murder. A person who murdered is not allowed to be seen as anything other than murder. It seems that there is no blood between a free man and a free man.
If this is the explanation, then it is certainly possible to understand that this is also true in cases of accidental death. The serious offense has still been committed, and it does not need to be actually punished in order to get rid of the mitigation. We want what is before our eyes to be only the offense of murder.