If I had to guess, and it is an educated guess, I would say that poor Christopher Chavez grew up hearing the same examples of Witnesses who were protected by invisible men that only the assailants could see. Chavez heard time and time again of Witnesses who were subject to attempted murder, rape, and armed robbery only to be miraculously saved by "calling upon Jehovah."
Many have commented on this website how the Watchtower takes artistic license and turns incidents with JWs into fishermen's tails of the one that got away. I have no real evidence, but I will make the allegation that the Watchtower fabricates the stories of miraculous saves of JWs from acts of violence. There are too many documented cases, like Christopher Chavez', where JWs are murdered and raped.
The Watchtower as far back as the early 1990s got to the point of refusing to state that a person should even attempt to use force in the defense of one's self or an innocent third party. Saul has slain his thousands and David his tens of thousands, but Jehovah doesn't seem to want you or I to even throw a punch to save a life.