Maybe, he'd certainly have a claim to it. Probably a harder one to defend since he chose to pursue instead of retreat and that Kyle chose not to fire despite having the opportunity to do so until after Grosskreutz had pointed his weapon at him. This all being on video.
Do you think the DA would have pursued charges against Grosskreutz for first degree murder?
Section (3)(c):
948.60(3)(c)
(c) This section applies only to a person under 18 years of age who possesses or is armed with a rifle or a shotgun if the person is in violation of s. 941.28 or is not in compliance with ss. 29.304 and 29.593. This section applies only to an adult who transfers a firearm to a person under 18 years of age if the person under 18 years of age is not in compliance with ss. 29.304 and 29.593 or to an adult who is in violation of s. 941.28.
941.28 relates to NFA controlled SBRs.
29.304 and 29.593 are specific to those involved in hunting.
Careful what you wish for there...
You should look up the ROE for a roadblock.