Steal glitch.
I made an arena deck with many different pillars and sanctuaries in order to test it out.
The Steal card does not appear as being "Played".
Basically, if the AI has enough quanta, and it's permanent field is full, and you have something it decides is worth stealing, it will try to use steal, and instead of it actually playing, the permanent just gets zapped and the card was never played.
I suspect this is because the permanent destruction effect actually happens BEFORE the card is actually played and disappears from hand.