[confirm]Kederekt Leviathan & co leave copy in gy-Necromancy

Describe the Bug:
When Kederekt Leviathan is returned from its owner's graveyard to the battlefield via Necromancy, Necromancy is returned to its owner's hand, prompting Leviathan to be sacrificed as intended.
A copy of Necromancy ends up in Necromancy's owner's graveyard in the process, though.
Which card did behave improperly ?
Necromancy in conjunction with Kederekt Leviathan.
Which update are you using?(date,name)Which type(Duel,Gauntlet,Sealed Deck)
CoRM15 mini4, duel
What exactly should be the correct behavior/interaction ?
Necromancy is returned to its owner's hand without putting a copy of Necromancy into its owner's graveyard.
Are any other cards possibly affected by this bug ?
Also tested Animate Dead -> same bug
Also tested reanimating Venser, Shaper Savant and targeting Necromancy with Venser's triggered ability -> same bug
When Kederekt Leviathan is returned from its owner's graveyard to the battlefield via Necromancy, Necromancy is returned to its owner's hand, prompting Leviathan to be sacrificed as intended.
A copy of Necromancy ends up in Necromancy's owner's graveyard in the process, though.
Which card did behave improperly ?
Necromancy in conjunction with Kederekt Leviathan.
Which update are you using?(date,name)Which type(Duel,Gauntlet,Sealed Deck)
CoRM15 mini4, duel
What exactly should be the correct behavior/interaction ?
Necromancy is returned to its owner's hand without putting a copy of Necromancy into its owner's graveyard.
Are any other cards possibly affected by this bug ?
Also tested Animate Dead -> same bug
Also tested reanimating Venser, Shaper Savant and targeting Necromancy with Venser's triggered ability -> same bug