The bottom line test is: "What would a reasonable person do under the circumstances." And that is ultimately a jury question.
Sometimes we hear one say: "I'd rather be tried by 12 than carried by 6." However under the laws of state in which I live you only have the right to use deadly force likely to cause death or great bodily harm if you are in imminent danger of death or great bodily harm. There must always be both reasonable and factual grounds to believe that such force is necessary to prevent a "forcible felony" such as rape, robbery, murder, aggravated assault, aggravated battery, kidnapping, etc. Obviously one will note that worthless checks, sale of drugs, or grand theft are not forcible crimes.
In deciding whether defendant was justified in the use of force likely to cause death or great bodily harm, the Jury must judge the defendant by the circumstances by which he was surrounded at the time the force was used. The danger facing the defendant need not have been actual; however, to justify the use of force likely to cause death or great bodily harm, the appearance of danger must have been so real that a reasonably cautious and prudent person under the same circumstances would have believed that the danger could be avoided only through the use of that force. Based upon appearances, the defendant must have actually believed that the danger was real.
IT IS EXTREMELY IMPORTANT TO REMEMBER THAT IN ANY CASE INVOLVING THE ISSUE OF SELF-DEFENSE THE FACTS ARE THE CONTROLLING FACTOR IN DETERMINING IF THE DEADLY FORCE USED WAS OR WAS NOT JUSTIFIED. JUST ONE FACT CAN CHANGE A CASE FROM SELF-DEFENSE TO ONE OF MURDER OR MANSLAUGHTER.
T IS ALSO IMPORTANT TO REMEMBER THAT THE BEST ADVICE A LAWYER CAN GIVE HIS CLIENT IS: KEEP YOUR MOUTH SHUT.
Based on the facts given I do not have an opinion and would have to get some additional information before I could an opinion. However if there is a reasonable doubt then one should be found not guilty. Although that might be what ultimately happens that doesn't mean one might not be charged and/or prosecuted. Which reminds me the election of a prosecutor is extreamly important and we should all strive to elect pro-firearm, pro-self-defense prosecutors/district attorneys.