Right, but I think they mean for that particular cause of false negatives quoted (counter overflow). There's no good way I can think of to mitigate the false ne

Right, but I think they mean for that particular cause of false negatives quoted (counter overflow). There's no good way I can think of to mitigate the false negatives caused by removing items never inserted into the filter since you have no way of knowing what was exactly added and what wasnt. There's a paper linked in the blog post that goes into a lot of detail about minimizing false negative probability.