Crucible of Worlds - Opponent access to my Graveyard
Opponent played my strip mine out of my graveyard whilst we both had crucible of worlds in play (screenshot is from start of turn after it occurred).
Game was Game 3 of Event #230018003. Was my fourth round of league.
Edit: Crucible of Worlds text 'You may play lands from your graveyard' so he should not have been able to play my land.