I'm not sure how much involvement you've had in real estate transactions, but verbal agreements carry no weight.
Agreements in real estate must be in writing, and signed by both parties.
I have been involved in real estate and have seen deals go sour.
The thing people don’t realize is a verbal agreement IS an agreement. If both sides agree it was in place then it is enforceable. When one side claims a verbal agreement and the other side lies & says it didn’t exist, the courts look at the BEHAVIOR of both sides, especially over long term, to see if they ACTED as if there was an agreement in place.
Once the owner explicitly says the guy has no permission, then the court can proceed appropriately.
You claim they MUST be in writing but it is not the case. It’s just not enforceable.
I recently had verbal agreement entered into a court case I was involved in. By criminal section 633.5 I had the right to record my landlord because he was violent. It is a very low standard of admission of evidence: a reasonable person standard.
So I was recording where the guy claimed that even though we did have an oral agreement, it was not enforceable. The court disagreed with him.
Not every agreement in real estate must be in writing.