If some dude in an expensive suit gets on TV and says a stock will fall then buys a couple billion in shorts and you do the same because you like his style the two of you aren't scheming to make it happen.

Likewise, if some guy in his basement posts on an internet forum about how he's sure a stock will go up and you feel compelled to buy some too you're not scheming.

Finally, if millions of people are collectively motivated by the idea that they just really dislike hedge funds, want to make some money, and maybe want to watch the world burn, so they buy into an increasingly ridiculous idea they're _still_ not scheming because they all made the independent decision to do so after doing what amounts to each individual's 'due diligence' and are not entering or exiting the position in concert.

The risk was there when these funds shorted 140% of the stock. Retail folks noticed the potential for a naturally occurring squeeze and shared the info with world.