#902479 tokyo
i play KC-Possession in turn 15. In Turn P15/2 i let my opponent buy a lost city. As I gain the lost city, my opponent draws an extra card (log says its a copper). In Turn P15/3 i only see 5 cards in my opponents hand to decide, a copper is missing.
I don't think this is a bug. Your opponent got the copper into their hand in the buy phase of turn P15/2 and subsequently discarded it.
Oh, you are right! Because the copper goes into the "wrong" hand, a discard happens after the lost city buy. Silly me :-)
Sorry for the wrong bug report, case closed!