Not a Lawyer (NAL) but my 2 cents.
Generally speaking, residential contracts stipulate three basic things: parties involved, duration, and cost. Now, when you start to say "theft" there are certain conditions that have to be met, depending on state and local statues regarding the definition of theft. But my understanding of 'theft' is whether or not the thief had the legal right to possess the item.
Example 1: I let you borrow by hammer, verbally, for 2 days. On day 1, it is not theft. On day 2, it is not theft. On day 3, I notify you to return the hammer. You don't respond. Day 4, I give you a demand letter stating the return of the hammer and file a police report. You don't respond. On day X (whenever I decide to sue you, file the case, issue you your notice) then it will be construed as 'theft' and a court date set. On day of, I can argue that it would be 'theft' based on the the background information and the current laws in place defining 'theft', and you can argue why it is not. Judge forms a verdict and decides whether or not the information provided will fit the bill of 'theft'. If so, you are now formally convicted of 'theft'.
Long story short, it isn't theft until a magistrate (or judge) says it is. We as civilians, can say whatever we want, but it won't have the force of law behind it. Go 1st amendment!
Here we have a presumed to be unique case where there is a rental contract between the two parties (Landlord and Tenant) where the Tenant has the legal right to inhabit the rented premises from the Landlord for X amount of dollars and for Y time.
If the tenant does not leave, or fails to pay rent, then it would be an unlawful detainer suit by the Landlord to 'return' the property back to the Landlord. At least, in CA where I am at.
Now thus far, OP said that the contract began on December (whether month to month, or year contract), presumably there wasn't a problem for January or February Rent. Otherwise OP would've discovered this 'problem' earlier. So we can safely assume that the move occurred within the past 3-4 weeks after the February payment. Or if the Landlord is an absentee landlord, even as early as the day after the contract was signed. Who knows? I hope OP has documented everything for presentation when this goes to court (or mediation for a settlement).
With all of this said, I believe there would be a number of legal and OP questions that needs to be addressed that will coincide with the ones that OP has already asked.
Since the Father was the one signed, was the son part of the lease? Or was this an unlawful subletting of the property? In most cases, this answer is easily answered, as it is the first thing on rental contracts. But if the son isn't on the lease, and there wasn't a clause that allows the son to inhabit, then there is also the consideration of additional 'breaches of contract' as there is now a tenant that lives (or used to live on) the property that shouldn't be there.
Here is where the 'loophole' I mentioned would take place. Because the contract (I assume) does not explicitly mention that the building itself cannot be moved, it does not necessarily mean that it cannot be moved. When I say cannot, I am referring to the legal right to move it and the physical feasibility to move. Here we can explore the two in further detail.
As for legal right to move, we have other examples of where 'rented' property are moved. Car rentals for example. It is a contract between you, the rental company, where you are allowed to use the car for its intended function (to drive) for a Z amount. Here the intent of the rental, is explicit, for the contract to work, you must be able to 'move' the rented 'property' hence a resounding "Yes" to the question.
As for the legal right to move a house well, it gets tricky. The intent of renting a house is habitation. Because the instances where an entire house is moved is so very little to non-existent (this is the first case I actually read about) a consideration for the house to NOT be moved is almost never included in rental contracts. Except of course, in mobile homes, hence all of the questions asking about what kind of 'house' it would be. So the lack of explicit exclusion leaves the door open (pun intended) for the implicit presumption that it would be 'ok' as long as it was returned at the end of the term and in a reasonable state of repair depending on State landlord tenant law regarding damages at the end of term. After all, the goal of a rental contract is a place to live, where it is currently located, and for how much. Not where it can be located.
This might be something the Father's Lawyer would argue. Because it was not explicitly stated, it would be reasonable (from their point of view) to move the house, provided that the house was moved back at the end of the term. But since it would be neigh impossible to calculate the damage to a house from the action of removing it from the foundation, the move, and subsequent relocation back, it is almost better to write it off as a loss and claim for the full amount of the house.
Since March hasn't come yet (and we don't know if this is a month to month, or year long contract) we can't say that the Father has failed to abide by the terms of the contract (paying X amount). Currently at time of writing, the Father still has possession (quite literal possession) of the house (excluding land of course) somewhere except at the intended location.
Back to the hammer example. If the hammer was returned back to me after day 1 and it was missing a head. Then there would be damages to the item I lent to you, and thus I would have cause to claim. Now whether it would be worth my time to sue you for the damages, that is something that depends on the person. There is a man in Aus who spent $71k on a $181 ticket. http://q13fox.com/2016/02/26/man-spends-71000-fighting-a-180-speeding-ticket/
Back to the rental car example. The cost of 'moving' the car after it was borrowed by you, is well you. Given I asked for it back after a set amount of days, it would be reasonable for you to also "move" it to me. If there are unreasonable damages to the car, then I would have a claim. If not, then no problem.
In this case, since the house hasn't been formally 'returned' to its intended place, it would be presumed to be the Father to return the item. But as for whether or not he will pay. Who knows? If he doesn't have this as part of the insurance claim. Let them deal with the mess of paying for the cost. So for all intents and purposes, we can safely presume that OP does not have means and responsibility to move the house back.
My guess is a team. But not your team. The insurance company's team. Chances are, given the different levels of tom-foolery here, there will be different types in play, insurance, residential, etc.
Again with the car example. If you left the car rental on your driveway and the rental company came to repossess it. They don't own your driveway now. But rather, they can file a lien against your driveway (and house) as we result to pay for any damages and cost to repossess the car.
With the current situation. You can potentially find yourself the new owner of a moving company if it is something that is offered as a settlement and you accepted. For the time being, I don't think you will own the land it is currently sitting on.
Well, if it was moved once. It can be sure moved twice. I don't think you will like the results however.
The permit to move, especially oversize loads such as this, would almost certainly need a permit by the Department of Transportation or equivalent in your state. In such permits, it would state clearly who is requesting the permit, what is being transported, and when it will be transported and whether or you have the legal right to move the item in question. So yeah, I guess there would be a permit. But then who knows, given the situation, Father owning a company, such a permit might've not been granted.
They just showed up one day and moved the darn thing.
In summary OP, relax. Let your insurance do the heavy lifting. Expect a large payout in the end if everything works out just fine.
File a report with the police (as you did) File a claim with your insurance (as you will do) Talk to your neighbors and document and recording everything that has transpired.