OK, did you catch Shuckle in the Friend Safari? Pokemon in the Friend Safari have a chance to have their hidden ability. Since there are no Shuckle hordes, then that is the only real way it could have its hidden ability.
As for the pokeball, the heal ball is the only one that is currently available in X and Y that is even remotely pink. The Love Ball (from the Johto games) and the Dream Ball (from Gen V) are the only other balls that are pink, but to the best of my knowledge neither are currently available in X and Y.
Here is a list of all the pokeballs if you want to compare what you have to the balls on the list to see which is yours.