Of course it´s possible. Even highly likely. First bet is on bad drugs, and that they will be able to find out. Second bet is a little bit harder, and I don´t think they have the ability or knowledge to examine. For some sensitive people, the combination of high volume and a specific beat, will interfere with the heart rythm, and can in rare cases lead to death. However, rare, and thta two should drop dead in one festival sounds far fetched. So, betting on drugs in some form.
In what way did you just quote the post you replied to?
So, if some group would have done that, don´t you think there would be more than 2 victims???