What I expect to happen was...
I expect that the block ( with above the railway) after having deactivated the redstone returns to its normal state without breaking.
What actually happened was...
The rail, when the block of cobblestone back down, the rail breaks and shouldn't happen.
Steps to reproduce
1. Place a sticky piston with a piece of cobblestone pointing skyward
2. Place a piece of cobblestone or other on the piston.
3. Place a lever next to the piston
4. Turn the lever
5. Deactivates the lever
6. This is the result
Sticky pistons can only pull one block.