I pay excessive money at a restaurant to ensure I have to do no work and everything within reason is edible. If this is not the case when I get it, I love nothing more than sending it back, and if I don’t think they’ll not mess with my food or give me any attitude I will leave and they’ll eat the loss (and maybe the tails).
What if dark matter is some form of black hole or exotic ultra dense material made entirely out of the missing antimatter, which for whatever reason doesn’t otherwise interact with electromagnetism? 2 birds, 1 stone.