Powered pistons drop as items in creative

When I placed down a piston and it was powered by a Redstone torch,I expected that when I destroyed it that it would disappear as I was in creative mode however the item was dropped as if I was in survival mode.

To repeat this glitche place a piston down in creative mode,power the piston using any kind of Redstone such as a torch or a switch, while still in creative mode destroy the extended arm of the piston and you will see that the piston item will drop