The increased short interest is oddly bullish, in my view: it represents a pool of shares that must be covered as share prices rationalize. In essence, shorts taking a position in ACAS bet the dividend won't be paid, or that share price declines will offset paid dividends. These must be the case for short-sellers to maintain their positions, because the alternative is that short-sellers must pay the dividends to the holders of the shares they've sold short. Short-sellers' theory requires that past performance not be an indicator of future results, as ACAS' past performance includes the declaration, since a 1997 IPO at $15, of over $29 in dividends.
Short-sellers banking on an illiquidity-related collapse are essentially playing chicken with a train that's been building momentum since ACAS' CEO began doing employee-led buyouts in the 1980s. ACAS' management either has a pipeline full of portfolio comany sale deals in various stages of closing, providing a source of ongoing liquidity without need to access capital markets, or management lied on the last several conference calls.
I don't understand the short play, unless it's a short-term confidence play, or a bet that everything here is a direct lie.