You are able to right click through pistons while they are extending / retracting. I cannot verify if this bug happens on extending or retracting, but I can say that I can recreate the bug easily.

I made a mud farm which works by:
1. Place a dirt against a piston head
2. Dirt turns into mud
3. Push mud block away

I found this bug by holding right click on the piston, in a way so that my crosshair was still aiming at the piston body when it extended.
This glitch is not related to the mud block, specifically just the piston. The farm I made is just an easy way to recreate the bug.

You are able to right click redstone dust, which breaks the machine, and you can even open a chest through the piston.

I have attached pictures that show what happened with the redstone dust, as well as the machine used to recreate the bug
(i tried to attach the world i recreated it in, but the file was too big)