All I know is that the team of lawyers said that if the gun was unlawful then he could not claim “lawful” self defense. It is no longer “lawful”. In which case the self defense argument had no weight and the jury would not even consider it in their decision.
So far this trial has shown that “what it is supposed to be”, or even “what the law is” has no influence at all.
This is political theater disguised as a trial.