Pistone bugging out.

What actually happened was...:
While build mechanism that should open gate by making right combination of levers, suddenly while activating lever that triggered mechanism at should activate this specific pistone it gone both ways making this weird thing below. I though it could happend becouse of World Edit which allows to do such things, but I dont think it has something to do with it.

Steps to Reproduce:
1. Build the machine i linked below (I dont know is this one time or becouse of some redstone).