I am going to say it depends on how good his lawyer is.
At a guess, he is going to have to pay back the money that the county paid for the additional power.
Since the power is metered and you can get a general idea of how much power each miner took and if he can prove when it was put in. And then it's a bit more math to figure out the cost of the additional cooling. Add to that amount a bit of a penalty and the theft charges should be dropped / reduced to probation at that point.
For the other things he is accused of, it depends how bad it was.
If he setup a separate VLAN for his equipment that kept it away from the rest of the network and he did it properly then it's one thing.
If he put unknown / unapproved equipment on the network and set it up so that the data his miners used was of a higher priority then the rest of the users then it's another.
As an IT person, who deals with security a lot it's easy to see how this could become a case less about mining and more about what IT can and cannot do with the network that is under their control.
Since this is local to me, and since I am in the IT world, I am going stay out of a large portion of any discussion about it since my view really is. 'Nail his ass to the wall, he was screwing around with miners and costing the county I live in extra money while my taxes were paying his salary'
-Dave