[PhantomGremlin]

But no sane hedge fund will short the stock without also buying a call option

Bill Ackman reads this and says "Oh, shit ... you can do that? Why didn't someone tell me that before I lost about $1 billion shorting that POS Herbalife pyramid scheme?"

In other words, sometimes "insane" hedge funds are run by BSDs[1] who are convinced they are the smartest guys in the room. They're so convinced that a stock is worthless that they don't bother doing something prudent like buying protective calls.

And then guys like Carl Icahn buy HLF stock just for the lulz, knowing that they are giving Ackman a very painful galactic wedgie.

Wall Street is definitely Adult Swim. And occasionally joker hedge funds need to be reminded of that.

[1] not Berkeley, but Liar's Poker