Someone going around injecting people with drugs is just a rumor. There plenty of videos out there showing what really happened. Which was people being crushed.
Who the hell pays good money to listen to this crap anyway? It's junk rap. It's all "yo yo yo, muthafucka this n muthafucka that." It's only going to attract the trashiest elements of society. If you're caught in a sea of thousands of them with no way to move, nobody in the back is going to give a shit about your safety as they push to the front to get their selfies for instaface likes. It also doesn't help that this rapper apparently has a history of instigating chaotic and belligerent behavior. Encouraging them to "rage" and ignore security barricades to get closer to the stage.