Because America is so hard on gun providers....Noone is q Miller anymore. Accept for defense. But the accessory to Murder is not out the window if any other key witness steps forward and implicates him, hence removing the prosecutions need for his testimony against the shooter to save himself. His baggage cart will absolutely hurt him at the time of the draft and should have if it is ignored. If someone from the victims fam doesn't take a shot at him before that anyway.
You cannot tell me he had no idea what "could happen" when he drove up to the location, and there wasn't any gun play until he did
Miller has no chance of being prosecuted or getting in trouble. His car is the main form of evidence as he had his dashcam on. If there was anything actionable against him, it already would have presented itself.