Two things wrong here, first the guy shoots the drone down which was definitely illegal. Second thing though is that they only found out it was shot down after the police investigated? Why did they not see it fall from the sky? Maybe it was that they were flying BVLOS? Not being the drone police by any means becasue I have said many times that I have flown BVLOS for a few seconds. But, if you are an organized group, flying commercially, or doing something that is visible to the public, you need to be in VLOS unless you have a waiver. Which it didn't say if they had one or not, but chances are they didn't.