The horror that is "we'll assume the worst" disclosure rules

Recently a teacher's aide in Michigan was fired for cause. The reason? She failed to supply her employer with her facebook username and password after a complaint was filed by a parent. Reporting is a bit scanty on whether or not there was a formal inquiry into the event, but she was repeatedly asked for her credentials and she said no every time. So she got fired.

The real kicker is the following paragraph:

In a letter to Hester from the Lewis Cass ISD Special Education Director, he wrote " the absence of you voluntarily granting Lewis Cass ISD administration access to you[r] Facebook page, we will assume the worst and act accordingly.
Worst in this case is that the image was worse than the complaining parent described. As this is a school district, there is a whole lotta worse it can get depending on how far they want to go. They didn't end up pressing homicide or child pornography charges, so that's something, but they still fired her.

The "assume the worst" part is the critically wrong aspect of this.

Having spent time mucking about labor law in a previous life I have some appreciation for how the still largely unionized Educational workplace in the US works. When it comes to settling union grievances, which is an extra-judicial process up until the final step if things go that far, the right of due-process and 'innocent until proven guilty' is very much enshrined in the supporting legal statutes and precedent. And once it hits the courts (if it doesn't go into arbitration) the legal footing for those two principles is much stronger.

"Assume the worst" is guilty unless proven innocent, which is very wrong.

Wearing my info-security hat, I don't subject a user to disciplinary actions (or recommend such) until and unless strong evidence exists to support such an action. After an allegation of wrong-doing, the user suddenly stopping cooperation is actually a valid tactic on their part (just don't destroy evidence). Things get more complicated if evidence we need is held in non-company domains such as gmail, but there are ways to get at that information without demanding account login data.

Of course, private sector corporate employment agreements can abrogate a surprisingly large number of civil rights so long as the actions are entirely within the private domain. But this case was a public school district, and that's different. They actually get the civil rights private-sector workers sometimes are excluded from, a point some public-sector administrators forget sometimes.