You get different results because your not actually doing the same thing. Walking and walking off a cliff may involve the same muscle motions, but they are most definitely different.
But let's give you the benefit of the doubt and assume for a moment that tidal forces below the cliffs were strong enough to dislodge the anchors of a few otherwise stationary shellfish, I don't think said motions would represent an act of defiance.
ps: I am not in possession of anything called a "not actually", so I don't believe it could possibly be doing the "same thing". Or anything for that matter.