Things are normally ruled out before they are ruled in. Remember May repeatedly saying that there would not be a General Election until 2021. Or Cameron repeatedly saying that if by any possibility there was a vote to leave the EU he would stick around as Prime Minister while the mess was cleared up? Or every single LibDem candidate making an individual pledge to oppose tuition fees irrespective of how the election turned out? Pledges and promises by politicians are almost invariably written in water.