Politicians missing the point when they speak

When Joan Burton, standing in the Taoiseach’s place in the Dáil, announces she expects water charges for a family of 4 adults to be less than €200 she was, we are told, speaking on a personal basis.

As she was answering questions in the absence of the ‘leader’ she was surely voicing government policy?

Taking the above to its logical conclusion one must infer that when the Taoiseach answers questions he is also exposing a personal view on policy. Am I missing something?