Some months ago, after a similar incident, a new rule was instituted in the LurkMeister household: if there’s anything in the oven and the oven is off, a dishtowel is left hanging over the door (not on the handle, but over the door itself so that one end is actually inside the oven).
Sometimes I forget to take something out for supper until I’m leaving for work in the morning; if I put it in the fridge it doesn’t defrost in time for supper and if I leave it on the counter the cats will get at it as it defrosts. Putting it in the oven is the best solution.