Hang over plus work

It must be one of my most boring freelance job ever but I can't complaint much. I send in my friend to replace me n work at the restaurant for me n guess what the owner did? He send my friend home! How can he do that? Why can't he make a phone call to me before he found out there was another photographer working for the function? This is very unorganized n unfair to my friend. What should I do?