I'd err on the side of caution in even considering the use of the word dissociation or making a mental connection to the idea that there's something lurking underneath this 9 yo boys psyche.
If the behavior is fine apart from being undecided in what to call you, your road is paved in gold.
A little consternation harmed noone, really. Then again, maybe it's not something at the forefront of his thoughts? You're an adult. Young boys have many, many things to think about. Games and legos and whatnot.