Argument about "innocent until proven guilty" with "stand your ground" law

Before the law, the person who shot will be accused of crime but they would be assumed innocent until proven guilty. Thus, the government has the responsibility to prosecute the shooter and find out if they had the right to shoot or not. One of the defenses may be "self-defense" but it has to be proven in court.

After the law, when the person who shot says that they acted in self-defense, the crime is defined as the attack of the person who was shot, because self-defense is appropriate response in such situation and is not a crime. Therefore, the person who attacked is first accused of attacking the person who defended themselves, and the government has to prove that they indeed did attack. Even though the attacker is pressumed innocent until proven guilty, when they are dead, the only testimony is that of the defender and they physically cannot defend themselves (unlike when the alive person who shot). Therefore, there is never ground for disproving that the attacker indeed attacked and the case is dismissed.

In the first case we assume that the attacker's dead was unnecessary and the innocent person died. The mistake we can do is when we find the defender guilty when indeed they defended themselves. Thus, we can put innocent person to jail.

In the second case we assume that the defender is innocent and the attacker indeed attacked the defender. The mistake we can make do is when the attacker never attacked and they are the innocent person who died.

Because in the first case the person is alive and they can defend themselves, we are in position to disprove any false positives (the defender was not defending themselves [false] when they claimed they did defend themselves [positive]). In the second case we are not in position to disprove any false positives (the attacker was not attacking [false] when they are assumed that they did attack[positive]) because the attacker is dead. Therefore the law is weaker in the second case because in all cases we have to believe that the attacker indeed attacked - by default we prosecute both crimes (attack) and innocent people (those who did not attack).