Flutter has the good-to-have problem of sky-high market expectations.  It announced its interim results this morning. On all important metrics — revenue, gross profit, operating profit, Ebitda, earnings per share, US revenue, and US Ebitda — it beat the market’s consensus forecast. Despite beating market forecasts, the share slid sharply this morning. It was down six per cent at one point. It's currently down four per cent.  Why did it fall? Clearly, the results disappointed the markets in some way. As we've seen the headline figures were strong. Flutter's communications strategy emphasised that the US business had, in this half…