This always happens to me when I play a card that exiles something from an opponent's grave but there is nothing there to exile. Then, until the end of the turn, if they kill my card, it goes into exile. I have been using Sungold Sentinel + Extraction Specialit, so often the game involves playing Sentinel turn 2, and when it dies, playing Extraction specialist turn 3 to bring it back - but depending on when it's killed, it just goes into exile for no reason. I think it only ever happened against red decks though, at least once with Lightning Strike and once with Play with Fire. I started paying more attention after the second time it happened.
This always happens to me when I play a card that exiles something from an opponent's grave but there is nothing there to exile. Then, until the end of the turn, if they kill my card, it goes into exile. I have been using Sungold Sentinel + Extraction Specialit, so often the game involves playing Sentinel turn 2, and when it dies, playing Extraction specialist turn 3 to bring it back - but depending on when it's killed, it just goes into exile for no reason. I think it only ever happened against red decks though, at least once with Lightning Strike and once with Play with Fire. I started paying more attention after the second time it happened.