WTH??? At some point was the "good guy" going to call 911? "Carry" is a broad term. Carry how? Carrying it in one hand, grabbing the foregrip? Slug over the shoulder, pointed up? Slung across the chest angled down? Or carrying it in a low ready? Details matter. Shooting someone with a slung rifle on their back, pointed up, might be an issue. Shooting someone "carrying" the rifle in a high or low ready....probably ok. I'm all for exercising your right to carry a rifle in public, even though its asinine. However, if you are dumb enough to walk into a public gathering location with a rifle, hand on grip, in a low or high ready, you deserve what happens to you.Another scenario.
Good guy goes into the bathroom and surprises bad guy already in bathroom. The bad guy tries to attack good guy but good guy manages to subdue or knock out bad guy and take his rifle. he does not see the other guns in a stall. He does not want to leave the rifle with the bad guy so he takes it and leaves the bathroom. Now you have a good guy with a rifle leaving the bathroom just like the bad guy was before. Good guy is understandably uncomfortable with the rifle in a mall so maybe he clumsily tries to hide it, maybe he nervously fumbles around with how to carry it, whatever. He probably will not look calm and harmless.
This does not change any information that Eli would have seen - some guy coming out of bathroom with an AR-15 rifle.