Two remarkable things happened this morning: England beat Australia in a game of cricket and Slaughter and May hired a partner from another firm.

Given such seismic events, it would be little surprise to see a pig in a bowler hat take to the skies over the Royal Exchange this afternoon.

Slaughters' decision to plunge into the lateral market to capture the signature of capital markets partner John Moore should not be read as a sign that the firm that has always been the poster child for organic growth is changing tack, so much as evidence for the growing importance of the Morrison & Foerster partner's practice area.

Moore is co-head of the US firm's Chinese capital markets practice, and, having worked in-house at Goldman Sachs and been chair of the Hong Kong Listing Committee, few in the city will have a better overview of the market.

So it's clear what Slaughters saw in Moore. But why was Hong Kong in January 2014 the time and place for the firm to buck 125 years of tradition and hire a lateral partner? The answer lies in the rapid growth of its US rivals in Hong Kong. "We have been looking at this for a little time now because there has been quite a sea change in the Hong Kong market," explains Paul Olney, Slaughters' practice partner. "A number of US law firms are not only increasing capacity [generally] but taking on a Hong Kong capacity."

For Slaughters, which has always relied on its famed best friends network to buddy up over deals that require non UK-law capacity, the bullishness of American firms such as Davis Polk & Wardwell and Simpson Thacher & Bartlett has forced it to adapt.

Olney continues: "What became clear in the partnership was that it's become increasingly difficult to keep teaming up with a US partner, particularly in Hong Kong capital markets. "It's a market that we have to be in and we felt we had to respond to that."

That's not to say the decision was taken lightly. Indeed, there was a full partner vote even to approve the strategy before any approach to Moore, who has been known to Slaughters partners including existing Hong Kong capital markets partner Benita Yu since his Goldman days.

Nor does it mean that the floodgates will open. "This is a new departure for us," Olney accepts. "There's no glossing over that. We never said we would not hire laterals. But is this going to lead to a whole spate of them? No absolutely not."

Nevertheless, no one in either London or Hong Kong is likely to see this news as anything other than a sign that the growing threat from US firms means City institutions such as Slaughters might have to rethink their strategies. Interesting times await.