Some redstone components wont de-power properly even in non quasi connectivity configurations. This is easy to replicate with pistons though Ive seen some tripwire hooks get into a kind of locked powered state but couldn't replicate.

To replicate the pistons place ~10 pistons facing horizontally separated by a block gap between each, a line of blocks running over the top of them and dust over that. Place a redstone source over a piston (important for some reason) then de-power it. Some pistons (not all) will remain extended.