Zack:
Komodos were widely thought to kill prey by septicemia - bacterial infections of the blood - that was proven to be untrue.
The problem with that theory is that the death of large prey occured too quickly to be attributable to systemic bacterial poisoning. It's one of those urban legend things - sort of. While they have a mouth full of many strains of nasty bacteria, that's not what was causing rapid swelling and blood pressure/clotting changes.