Piston being powered when it shouldn't be possible.

Put the summary of the bug you're having here

What I expected to happen was...:
The piston to not be extended/ powered.

What actually happened was...:
When I redstone is powered 2 blocks above the piston and there is no block above the piston which means it shouldn't be powered as its not being directly powered.

Steps to Reproduce:
1. Place a redstone torch 2 blocks above the piston to the left or right side by 1 block
2. place a piece of redstone on a block that is above the piston but still keeping the 2 block gap and is being powered by the redstone torch.
3. Place a block on the piston and it will extend when it shouldn't, remove the block that is on top of the piston and the piston should still be extended with no redstone power connected to it.