when you connect a sticky piston to redstone thats active and you break the sticky piston it gets lava particles

What I expected to happen was...:
The sticky piston should of made sticky piston particles.

What actually happened was...:
When I broke the sticky piston that was connected to the redstone it made lava particles.

Steps to Reproduce:
1. first connect the sticky piston to active redstone
2. ...then break the sticky piston
3. ...then it makes lava particles