Think of this for a second. You taser someone, get closer and then the motherfucker stands up, hits you with something and proceeds to escape. You don't know whether he has a gun or a knife in his pocket, you are still standing but are not sure whether you're injured because of adrenaline and that same guy is running in some direction, you don't know his intensions in worst scenario he might have an explosive vest on and at that exact second rushing into the crowd, you can't surely say whether he's mentally ill or not. So tell me, are you going to risk it and use taser which already failed once or pull out your gun to prevent the worst scenario?