Easy:
Kumzits gets cancelled - goes to iPlayAmerica instead - meets a friend from elementary school who is not the best person to be around - becomes friends with him because he's mad at the establishment (but obviously doesn't think that the friend will have that bad of a effect on him) - slowly but surely they go lower and lower and he becomes part of that crowd - after sometime trys weed - some friends are doing other drugs - he trys other drugs - he gets addicted after some time - then the worst happens c"v.
That's how.
Let's just call that a long stretch rather than easy.
Yes that is a long stretch and if that actually manifests then that I imagine a lot more is going on then just a cancelled event.
IMHO one of the worst parts of this whole episode is all the brewing hatred, finger pointing, he said/she said, and other non-constructive talk that will dominate all of these peoples yom tov meals. All the lashon hora that has and will be spread over the next 2 weeks is frightening.