I don’t think this case was ever a “non issue.” Chloe is the victim and it’s LE’s responsibility to represent her interests and determine what happened. I think LE no doubt conducted a thorough investigation and interviewed a lot of people, in addition to watching the video frame-by-frame. They probably also retrieved records of what SA had to drink, if anything, as well as medical records and other info we haven’t even guessed. So it doesn’t strike me as odd that it took about three months to present the case to the DA who then filed charges. It seems clear that there must have been enough evidence to charge negligent homicide and that it couldn’t be written off as an unfortunate accident. I doubt LE wanted to charge a distraught grandfather, but Chloe is the victim and LE is working on her behalf only.