I just completed my CCW training a few weeks ago. The instructor said nothing about firing a warning shot being a felony; he said it was a bad idea, in part because the bullet could hit someone or something else, and the shooter would be liable for that.
my gun lawyer in my legal class, who used to be an ada, said a warning shot can be construed at trial to indicate the shooter was not in immediate danger. there is right and there is wrong and there is the legal system, not to be confused with a justice system.