I highly doubt a weasel would eat a mouse bait pellet. weasels are carnivores.
If the poisoned mice died before the weasel found them then the weasel is probably still alive. A weasel wouldn't eat an already dead mouse. If the weasel caught a live poisoned mouse and ate it, the weasel may have died too.
I'd sooner clean up a few weasel turds than a thousand mouse droppings. A weasel has a hunting territory and circuit it follows. A weasel usually takes 7 to 10 days to make it's circuit. so odds could be the weasel moved on but could well be back.
Should lacquer a pair of the weasel droppings and make some social distancing earrings for your wife or girlfriend.