I don't think he will have one. I looked for relevant case law and other areas of state and local law. It appears to read as if:
I were to go over to your house and I did not have lawful control over your property... I would require a permit to conceal. You giving me permission is not an affirmative defense. You might be wondering, that someone can do whatever they want on their own property. This is not true in statutory cases where government interest is considered weighty. For example, I can not give you permission to smoke crack or be cruel to animals (animals are considered chattel) on my land, just because it is my land. The statute prohibits both cases, even on private land.
There might be some interesting ways around that however. If you were to give me temporary control, or shared control, then someone might say that would be a defense.... but I don't see it tested in court.
This is not legal advice. This is an unqualified opinion.
Let's be honest, why would it ever be tested? If I go to my fathers land and my father tells me it's ok to concealed carry on his land, why would there ever be a legal conflict that would go to court for the position to be tested? Assuming it's an amicable relationship, which it would have to be for my father to allow me to carry a concealed weapon in his presence. If it's not, why would he allow it? You follow me?
But this is a different situation from the animal abuse or even crack. There are so many levels of difference it's tough to settle on one or even a few. At the top is the fact that you have a right to keep and bear arms. Granted the Supreme Court has clearly stated that is not an unlimited right, but it is a right. You do not have a right to abuse animals. So the analogy is not good to start. Further, the abuse of animals would be a crime that has affects that are visible or tangible. So from the standpoint of calling attention to the crime it's more likely to be noticed and therefore would have case law to follow it. You are correct that private property is not a blanket absolution against following laws. But the examples we are all using are not appropriate. Let's compare rights to rights first.
Maybe speech, since it's a closer right to 2A. I would argue that you probably don't have the right to yell fire in a theater (classic example used) if the theater owner gives you permission, but the action its self is deemed unacceptable because it results in the violation of someone else's rights. IE, I endanger peoples lives if I do that action. On the contrary, I would say that if I want to protest a business and that business doesn't want me on their property I can't be on their property. But if the business next door gives me permission to be on their own property I can. So to apply this here, imagine a law in a city which says that protesters must remain 50 feet from an abortion clinic. The assumption in the law is that the property owner does not want you on their property. But directly next door is a church and their property line is closer than 50'. I would say that if the church give permission to stand on their property, the law does not apply because the protesters have the permission of the church to be on church property.
Again, the above is all mere speculation and not based on case law mainly because it's not been tested and is not likely to ever be tested. That said, I would also challenge anyone to find a case where someone was arrested only for carrying concealed on private property where they had permission to carry concealed. I doubt that you will find even one instance. (The caveat here is that the person cannot have committed any other crime.)
