Does Marth's Counter ever get out-prioritized?

Looking at the hitbox of Marth's down-B, I noticed that his foot's poking out. Presumably, an attack would beat counter if it's hitbox was only touching Marth's hurtbox and not the blue counter box thing. Moves travel a certain distance every frame though; so it seems like it would be extremely unlikely. Does this ever happen?

I'm particularly curious about how this could affect counter edge guards against Fox's up-B.