There is a couple of angles that a few of the media outlets are now taking trying to "discredit" what this woman did.
1. She didn't really kill him the shot that killed him came from his own gun
2. She is a former cop, normal armed citizens wouldn't have the training she did to handle this situation.
First, lets get this straight, she did kill him, even if they found her bullet wasn't the one that actually made him expire, she still killed him, he would of gone on to shoot and kill more people that day if it wasn't for her shooting him multiple times.
Second, now her training and experience as a one time cop couldn't of hurt but there are many "normal" people out there that have CCW permits that have training of some sort whether they were former or current military, former or current LEO or if it is just someone that took a defense pistol course to better prepare themselves.
The media is really pathetic and it is typical that they would start looking to deflect attention away from the fact that this hero was a regular person carry a personal firearm for defensive purposes.