"...the senior brass approved of its use..."
There is a whole lot of information not in this article.
Brass can't just "approve" software, there are formal steps that need to be followed. Were these steps followed? Did Davenport follow the rules?
"...demoted him when he didn't turn it over,..."
Unless Davenport was stupid enough to take an Article 15, demoting him requires some level of Courts Marshal. There has to be a regulation he broke or a lawful order he refused to follow that would justify this action. I am sure that if this went to Court Marshal, the ADC would have reviewed the legality of any orders.
"Sergeant Mark Davenport, in his spare time..."
There is no spare time when you are in the military. There is no "off-duty".
To quote a favourite military movie: "Your heart may belong to jesus but your ass belongs to the corp!" Or in this case the Air Force.
I think the article left out some critical information here. Not that I would ever accuse a media source from selectively filtering the facts in order to further an agenda.
I would need a lot more detail before I can take sides with this issue.