State based actions are happening before they are supposed to
Ink-eyes is able to target creatures that go to the graveyard at the same time that he deals damage. No player receives priority before the ability has to be put on the stack.
Steps to recreate
1.P1 Attacks with Ink-eyes and another creature
2.P2 Chump blocks the other creature
3.P1 Can now choose the chumping creature as a target for ink-eyes triggered ability even though no player has had priority.