He's not "on the short side". If you read the article, he's talking about an arbitrage opportunity, which if executed properly, should not be net long nor net short.
Citron is on the short side. Their entire investment strategy of the company is to short assets, in this scenario the future is used as an arbitrage hedge, but overall yes citron is short biased on bitcoin.
Citron is not bitcoin neutral. They are short biased bitcoin as their website and twitter account reiterate. And a hedge doesn't mean "neutral." It simply protects you in the event that an investment doesn't go as expected.
The bloomberg piece says: “Left recommends shorting the trust, buying bitcoin futures”. He says in the video: “I don’t even care what happens to bitcoin”. Where is the short bias?