How many phones were videoing at the moment the shots started ? Hundreds at least. With all of that acoustic data and known locations there will in time be a total understanding of what happened and when.
Who’s going to pull all that data together and analyze it? If it’s the FBI, are they trustworthy?
If Garland starts arresting folks that analyze this, is anyone going to stop him?
Would it surprise us if they could erase recordings from our phones? Or make it illegal to keep these recordings?