In this context, 'thou shalt not kill' means do not murder and do not commit manslaughter. That is do not take someone's life without state sanction.
Junta doesn't impress me as a murderer.
There are 13 people (the judge and jury) who were in a better position than you to decide what Junta was, and they unanimously found that he was a manslaughter, not a murderer.
Have you EVER been in a serious tussle? Do you know the feeling of adrenalin pumping too fast? Even you are capable of this mistake.
Yes, and if we make it we will get about 5 years to decide that getting 'in a serious tussle' was a stupid and potentially criminal activity.
This rationale of yours tells us much about you, and says nothing of the person to whom you projected it.