According to this article, the DOJ may charge individuals who attempt to spread COVID-19 with terroristic acts/threats. Suppose that an individual, say Bob, is being assaulted or otherwise a crime is being committed against an individual for which it is generally appropriate to use self defense in response. Call the criminal Joe. Suppose this occurs in one of the fifty states of the United States (if your answer is state specific please note it in your answer).
Suppose that Bob coughs on Joe in an act of self defense and generally attempts to defend himself by spreading his illness. Suppose that an objective lay person and Bob himself believes that Bob is infected with SARS-COV-2 (causing the disease of COVID-19). Also, an objective lay person and Bob would feel that Joe’s actions if not stopped would cause imminent harm to Bob, but would not result in death.
Suppose further that Bob believes that his acts of coughing would act as a deterrent to reduce the chance of Joe assaulting/attacking Bob.
Is this a legally permissible act for Bob to do? Is there any crime Bob is committing?