When it comes to explaining why someone acted one way, the explanations I gave weren't mean to be a complete list. I just picked 3 things off the top of my head as an alternative explanation of events. It isn't like the explanations I gave are shifting, since I'm not proposing one as the definitive recount of what happened. But rather I'm saying to prove the shock claim, all other reasonable explanations have to be ruled out.
And there are many, including ones which reflect poorly on Hasan without proving he shocked the dog. For example he could have not shocked his dog AND been dishonest about knowing the collar's shocking capability. The key idea is that there isn't enough verified evidence to pick the shock-collar theory over the many other explanations including ones I'm not even aware of.