Bug 1: Abomination respawn timer is active in turn based mode, respawning in real time. If you have game speed set to the fastest, this means he almost immediately respawns on top of you before you've had a chance to end your turn.
Bug 2: If you quicksave and quickload while the Abomination is respawning, it resets his spawn position to the center of the gas filled room, instead of where you killed him.