The client is asking "how you will be verifying the fact that the footage is ours."
He wants to make sure that he, the client, is able to use the footage that I provide free and clear and that he has full usage rights. In other words, someone is not going to come to him and say "Hey, you can't use that"
I'll assume the responsiblity. I'm not stealing a movie clip or anything. How do I let him know that he is legally protected?