No one can. It's part of the curse. Yet somehow the Pokemon must be bypassing it.

[He watches in amusement, while Zack happily yips and waves his tail. Lucy perches on the footboard and warbles. "Eevo!"]

He would love such a walk. Just be careful if he smells food. He's not above crashing barbecues and cookouts and anything else he sees where food is involved.