Consider, too, the outrage over Christie's recent imposition of a 2% success fee on vendors (something Sotheby's are said to have introduced rather more quietly a couple of years ago), Sotheby's restructuring to target the top end of the market, the overnight doubling of their auction guarantee facility and a net margin for the first nine months of just 7.5% or $44m - just over double the amount they spent on legal fees fighting shareholder disputes in the same period.
What does this all point to?
Potentially a sea-change in the way top-tier auction houses present themselves to the world from now on.
Dan Loeb and Third Point grabbed all the headlines in the past year as they turned the spotlight on Sotheby's management style and what they denounced as the board's poor market performance. And the fact that Loeb targeted Ruprecht personally, demanding his resignation, meant that the latter's days at the helm were surely numbered once Loeb and two other Third Point candidates secured boardroom seats in May.
However, the boardroom battle was merely an indicator of a much bigger challenge that has faced the salerooms of Manhattan and Mayfair for far longer: how to make enough money to remain viable businesses in the long term.
Back in 2002, in the dark days as former Sotheby's and Christie's executives faced prosecution in the wake of the price-fixing scandal, I was asked during an interview with CNN whether this was the biggest crisis that the two leading auction houses had ever faced. My reply was that it was not even the biggest crisis at that point. What was the biggest crisis, I said, stemmed from the fact that for the most part auction houses only had two ways of making money: they could charge the buyer a fee and they could charge the seller a fee. The crisis came from the fact that even when charging 40% of the hammer price between the two ends of the bid, they could still not make a viable profit.
Merchant banks
Since then, the two great rivals have proved themselves masters of reinvention, first with guarantees, which gave them the potential to increase their slice of the cake while keeping consignors on board, then by extending the facility to advance guarantees, spreading business to their financial service arms in the process. Just as global banking was collapsing amid scandal all around them, Sotheby's and Christie's were effectively turning themselves into merchant banks as well as auction houses.
Soon they effectively became the biggest dealers in the world, cutting a swathe through the trade as they snaffled many of the plum private treaty sales, a business that accounts for around 10% of their turnover now and remains, along with online sales, the key battleground for market development.
Add to this the recovery of the post-war and contemporary market since 2009, and the continuously tumbling saleroom records - Christie's posting the highest total for any auction ever at a premium-inclusive $853m in New York on November 12 - and all should seem rosy in the gardens of Wall Street and the City of London.
So why all the boardroom brawling at Sotheby's?
At the heart of the dispute had been the issue of shareholder value. Effectively, Loeb was asking how a global brand such as Sotheby's, reporting sales totals annually in billions of dollars, could be making such little profit, with resulting poor dividends.
Part of the problem is the image that the likes of Sotheby's, Christie's, Bonhams and Phillips deliberately cultivate: in the public eye the auction world - especially at the glamorous end of bejewelled New York and Mayfair contemporary art sales - appears to be awash with cash. And, of course, it is, helping to create the air of ultimate luxury and exclusivity with which these brands wish to be associated. Money attracts money, after all.
However, less obvious to the untutored eye is the cost of building and maintaining this status.
The traditional auction house, especially at the top end, is quite an inefficient business model in many ways. Sources of revenue remain restricted, while costs can explode in many directions, such as salaries, administration and marketing.
The more competitive you become, the bigger the toll as consignment deals are cut to the bone. Savvy collectors with a trophy Bacon, Warhol or Basquiat to sell know that they can play Sotheby's and Christie's off against each other till they secure not only a zero-rated vendor's commission, but also a slice of the buyer's premium. Yes, the auction houses achieve a headline multi-million dollar hammer price, but with that go all the costs and, potentially, a loss - the bit the public does not see.
Nonetheless, the current restructuring of Sotheby's business to chase post-war, contemporary, Impressionist and modern art, along with Asian art and jewellery, at the expense of mid-market collectible disciplines underscores the undimmed allure of this high-cost, high-maintenance sector of the market. Along with Christie's they are putting more of their resources into chasing a smaller sector of the market.
With this policy comes increased risk, as the auction houses raise the rate of in-house guarantees on which they make more of a profit (when they work) and rely less on irrevocable bids provided by third parties which, while all but risk-free to themselves, add less to the bottom line.
New ways of doing business
What this tells me is that however high saleroom records climb, auctions at the top end will comprise a business model that couples ever-rising risk with an ever-mounting squeeze on profits as they chase the biggest prizes.
As the duopoly's in-house analysts and bean counters have shown over the years, though, there is always another way to do business. So there is always hope.
Witness the rise of private treaty sales, further incursions into the primary market through their growing number of global galleries, Sotheby's deal with eBay to create a new conduit for sales in the $5000-100,000 bracket, Christie's new buy-it-now venture and various other add-ons via their finance arms.
What we are looking at, in fact, are no longer auction houses in the traditional sense, but multi-national conglomerates specialising in luxury goods and wealth management exploiting every route to market in their power.
Do not be surprised to see them encroaching on new territory well beyond their well-trodden areas of activity. What more could they do, for instance, in developing new services via their real estate divisions? How much further can they move into the finance sector, grabbing a bigger slice of the wealth management cake? After all, many of their existing clients have stacked portfolios currently stewarded elsewhere.
One thing is certain: the big auction houses have to evolve constantly to stay in the game. Bonhams have shown what can be done in less than a decade and are now up for sale. Where will a new owner take them on the world stage as they vie for their place at the top table?
In five years' time it is likely that we will be looking at a very different landscape. If so, I would argue that it will be this moment - Ruprecht's passing and the ascendancy of the Loeb viewpoint - that will prove to have been the clearest harbinger of that step-change.
