By that definition, Tuberculosis which kills 1.5 million every year. Doesn't quite satisfy the bet by itself but a few lopsided months could easily be 1 million in a 6 month period.

Regardless, I don't think the lack of disease prevention was the intent of bioerror. The article says that bioerror is supposed to have the same outcomes as bioterror but I believe the implication is that it is also caused by a single human or organization.