Can the business owner ask for the carry permit ? I suppose; I don't know that it's prohibited by law. However, I'm not aware of anywhere in the Oklahoma Statutes that REQUIRES a permit holder to display it upon request from a private property owner (if I'm wrong, kindly send me to the section).
If the licensee refuses to show his license upon request, can the businessowner then eject him ? Again, I suppose; I don't know that it's prohibited by law.
But the part about OSBI ? A complaint ?? About what ?? Has to be a violation of a statute - what statute did he supposedly violate ?
Maybe you can expand on this a bit, if you know what his specific concerns are. If he's just generally concerned that he's going to "get in trouble", because of the interaction with the business owner, I'm not sure what would give rise to that trouble.