You are assuming it is possible to return. There may not be any practical way of returning the item if you don’t know who the liquidator is. It is not unlikely that the office space as well as the furniture was rented and there may not be much to sell. I imagine that the primary value would be in software created and there should be multiple copies
Also, if it is a computer that is over about 18 months old it has very little value. They may not want it.
I’d try to return the files. I’d send an email to someone as a CMA strategy and tell them I had the files and the laptop but if they wanted it back they’d need to tell me who to give it too and provide a receipt for proof I’d returned it.
If they didn’t reply I consider myself to have done due diligence and not worry about it.
The answer is really clear. It is not his property. It is the property of someone else.
At this point it is not the property of the person that owes him the money. It is the property of everyone else that is left being owed money in the situation.
He has no right to steal that property.
Make whatever excuse you want to justify stealing but it is theft all the same. Don’t be a thief is always a good way to live.
Is his honesty worth nothing more than the value of a used laptop computer?