I suppose Hearns could have gotten that information from Sabrina in a way that doesn't make her complicit in his murder. They were having an affair, maybe they met up earlier on Sunday August, 17. She could have told Hearns her husband was due home from work at x:xx and where he was working that day. That would not make her guilty of anything if she did not know he planned to murder him.
I'm certainly willing to consider she is completely innocent. But given the fact LE initially charged and arrested her, I'd like to know what that was based on. Doesn't LE usually consult with the DA prior to bringing the charges? It seems that KCSO has a bit of egg on their faces?
What seems risky, how did Hearns know Rob would be alone at the shop? Did Rob and he know each other?
The video shows a man walking towards the shop @6:01 PM. He appears to be carrying something heavy. Was it ever determined who the man was?
http://www.turnto23.com/news/local-news/man-found-dead-inside-bnsf-railway-company-building-081814