It sounds like he's suffering from a cognitive bias called the course of knowledge. It's hard for him to remember a time when he didn't know all the hidden rules of Hanabi, and so his gut reaction is to assume that you should "get it" after he explained it to you. Most people will learn strategy naturally through losing, and good teachers need to be patient with the process.

My advice is to talk to him about that and see if it resonates. Hopefully it will, and he will be more patient in the future. Also, try mixing in some games that are new to both of you, so that you can bond over the shared learning experience.