Do you have screenshots of when this happened?
Or (better!) a link to the game on hsreplay.net?
Piloted Shredder has been in the game for a long time and has been played very often (espeically now that it is back in the Arena card pool). Yours is the only report on this, so if this is a bug then it must be due to a very specific set of circumstances, that can only be reconstructed by knowing exactly what was going on in your games. (And if you overlooked something, then that too would become clear if you can share more information).
See How to share links to screenshots, videos, and replays for how to post extra information that cannot be attached or linked directly.