"Prosecutor: Shooting victim pulled gun on retired cop

"Undisputed" - where did you get that? Where has there been an opportunity to dispute this? The police have had possession of the weapon, the family hasn't had it, so no, they haven't had a chance, as yet, to hire an expert to examine the weapon. I doubt they would have permitted the family to have taken the gun from evidence and subjected it to a more credible blood spatter expert - so of course, one so-called expert (who probably wouldn't qualify as one anyway) is all that has testified as yet.

And trust me, if they could have found something to nail Pickerill, it would already be out in the media, which tells me, there isn't much that is credible? (Convicted felons don't count.)