/k/ here. Rifle bullets travel faster than the speed of sound. That means you will hear a crack and then a bang. The crack is the supersonic bullet breaking the sound barrier, then you will hear a bang, because the muzzle blast is traveling slower than the bullet. So at range when being fired on, you will effectively hear 2 "gunshots for every round fired.
Idk man, to me it sounds like at least 2 guns were firing at the same time. Who knows.
Good comment on pol:
Just for the record if he really did get 50+ fatalities from gunfire only, he's number 3 on the global high score list and number ONE on the USA high score list.
It wouldn't be hard to get that many casualties when firing directly into an unprotected crowd that big. He fired a lot of shots.