Yes.
Think of his reality as one strand of string that is being wiggled.
Think of normal reality as a second string being wiggled next to it.
As the strings coincide, his reality crosses into ours, and vice versa.
And he appears in our reality, and we in his.
Now, taking into account that it is said the same for my existence as well, what happens when all possible realities coincide and synchronize?
*meta-state theory brain ker-pop*
Ouch.