ClVlL IMMUNITY. A defendant who uses force or
deadly force that is justified under Chapter 9, Penal Code, is immune
from civil liability for personal injury or death that results from the
defendant's use of force or deadly force, as applicable
My take on the civil immunity clause. IANAL
If you used deadly force against someone the family can sue you in civil court and one of you must prove in civil court whether or not it was justified under Chapter 9 of the penal code. If it is found that you were justified you will have immunity. I don't think being no-billed or being found justified in criminal court will prohibit you from being sued, but it may help your civil case I guess. I don't think there have been any cases so I suppose every opinion has some merit.