Add a visual element to dropped life potions (after a demigod dies) to indicate which is poisoned. The special indicator is viewable only by the same team, so they have forewarning about their own poisoned potions. Maybe make it a green potion instead of a red potion.
I saw the text "MellowTigger killed MellowTigger +1200 gold" in game. At first, I thought it was a bug, but then I realized that I had picked up one of my own potions. *sigh* When the field is littered with life potions, it's hard to remember which are your own (or your teammates').