This is legally tricky. It is much better that “warning shots” be both judgmental and based on that particular event, than if they try to legislate its rules.
Typically, an iron clad defense for shooting is that “I was in fear for my life.” If someone testifies to just that, without wavering, rephrasing, dealing with hypotheticals, or other lawyer tricks in which they change their testimony, they are extremely hard to convict.
But if you fire a warning shot, it shows that you had at least two frames of mind, not just fear. And that can be a legal minefield.
Instead of saying you fired a warning shot, it would be far better to say you accidentally discharged your first shot, “because I was in fear for my life.”
Uh, no.