Insider trading (and the wider 'market abuse') can be extremely difficult to prove. The FSA fines a handful of people each year, and prosecutes even fewer. If

Insider trading (and the wider 'market abuse') can be extremely difficult to prove. The FSA fines a handful of people each year, and prosecutes even fewer. If firms chose not to trade, when they otherwise would have done (which seems to be the case here), based on insider information, that is nigh on impossible to prove.