I agree that an employee who VW fired might not be the most reliable character witness about her lol.
I also think there could just be a lot of gray area here. VW's bosses liked her a lot, it seems. But in many workplaces, there's "by the book" and then there's "how things really go," and this jail seems to me to operate far more on the "how things really go" side of that equation. (And I don't think people on the outside typically care all that much about what goes on inside jail, as long as it STAYS inside the jail).
VW's superiors imo also have a vested interest in making this seem like the perfect employee suddenly gone bonkers rather than talk about the quality of supervision THEY were doing over this jail and her, when that was THEIR job. For ex., they have a long, extensive list of escapes from that jail.
Apparently, this jail was known to be loosely run and VW was the assistant director of it- a loosely run jail. So I think it's entirely possible that she was both highly regarded there AND that she was also on that slippery slope of not doing things by the book for some time, until it finally went too far and culminated in this disaster.
Of course I don't know any more than any other outside observer but personally I'd just find the "slippery slope" theory more likely than the "sudden crazy turn" theory.